Wednesday, March 6, 2013

solving online area of a circle


CIRCLE:

A line forming a closed loop, every point on which is a fixed distance from a center point.

A circle is a plane continuous figure connecting points which are equidistant from a given point, known as the center.

The word circle originates from the Latin word 'circus'. Chariot races, very popular in the Roman era were either circular or oblong and eventually the word was used to describe the shape as well.


Area of a circle - Important terms

In order to find the area of a circle, it is essential that we first understand a few important terms related to circles.

The outermost portion of the circle which separates the interior of the circle from the exterior is known as the circumference.

The center, as already mentioned, is the point inside the circle which is equidistant from all points lying on the circumference.

The distance between any point on the circumference from the center is known as the radius.

A line segment connecting any two points of lying on the circumference on the circle is called a chord.

The longest possible chord of a circle is known as a diameter. The diameter equals twice the radius.


Solving the area of a circle

Consider a circle with center P. Let us denote the radius of the circle by 'r' and the diameter by 'd'. Pi (denoted as π) is a numerical value, which is a crucial number used to calculate various attributes of circular figures. Its value up to 2 decimal points is 3.14. In terms of the radius.

we define the area (A) of the circle as:                  A = π r²

In terms of the diameter, which is twice the radius, this equation can be re-written as:

A = 0.25 π d²

The area in terms of the circumference (C) of the circle is given as:

A = C²/ 4π

Examples and exercises of area of circle.


Example 1: The radius of a circle is 3 inches. What is the area?

A = π r²

A  =  (  3.14  ) ( 3 ) 2

A = (3.14) (9)

A =  28.26 in 2

Answer  the following :

1) The diameter of a circle is 8 centimeters. What is the area?

2) The radius of a circle is 5 feet. What is the area?

Tuesday, March 5, 2013

Half Angle Properties


Introduction:

Let we will discuss about the half angle properties. The half angle is the angle that is half of original angle. Tha is, the product of two half angles at an edge is equal to the original(full) angle at that same edge. We will develop the properties formulas for half angle of both sine and cosine.


Half angle properties formula for sine:


We should start with formula for cosine of double angle. That is,
cos 2θ = 1 - 2sin^2 θ

Half angle properties formula - sine:

Let us consider,


Then 2θ = α and the formula becomes:


Solve for,


That is, we acquire sin(α/2) lying on the left of equation and everything else on right,



Solving of equation gives the following sine of half-angle identity:


The sign of sin α/2 represents on quadrant in which α/2 lies.
If α/2 is in the first or second quadrants then formula uses the positive case:


If α/2 is in the third or fourth quadrants, the formula uses the negative case:


Example:

Find the value of sin 45o using the sine half-angle properties.

Solution:

The sine half angle formula is ,



Therefore,

sin 45o = `sqrt((1 - cos 90 )/(2))`

= `sqrt((1 - 0 )/(2))`

= `sqrt((1)/(2))`

= 0.707


Half angle properties formula for cosine:


Half angle properties formula - cosine:

Using same process, with the similar replacement of θ = α / 2. We want to substitute into the identity,


We get,


Reverse process of the equation should be,


Addition of 1 with both sides of an equation. We get,


Making division process on both sides of equation by 2


Solving for cos(α/2), we get,


As before, the sign we need depends on quadrant.
If α/2 is in first or fourth quadrants that formula uses in positive case:


If α/2 is in the second or third quadrants, the formula uses the negative case:


Example:

Find the value of cos 115o using the cosine half-angle formula.

Solution:

We need to find cos 115o

That is, α = 230°, and so α/2 = 115°.

Therefore, cos 115o = `sqrt((1 + cos 230 )/(2))`

= `sqrt((1-0.643)/(2))`

= `sqrt((0.357)/(2))`

= 0.422

We have seen about the half angle properties.

Monday, March 4, 2013

Geometric Area


The geometric area refers to the size of the interior of a planar (flat) figure. Area (A) is a two-dimensional measure. The square units that  an area is measured with square inches, square feet and square centimeters. Hectares and acres are also considered in some special cases. In the International System of Units (SI), the standard unit of area is the meter squared (m 2).

Geometric area of Square

Formula to find the area of the square:

Area of the square is calculated by multiplying the base times itself.
Area of square = side x side square unit.
Area = a2

1. The side length of the square is 10 feet; find the area of the square.
Solution:

Area = a2

Given: Side length= 10feet.
                               = 10 x 10
                   Area    =100 feet2

2. The side length of the square is 4.5 m; find the area of the square.
Solution:

Area = a2

Given: Side length= 4.5m.
                              = 4.5 x 4.5
                      Area =20.25 m2

Geometric area of Rectangle

Area of the rectangle is calculated by multiplying the base times the height.

 Area of rectangle     =  (length x width) square unit.

Area = l x w square unit

3. The length and breadth of the rectangle are 10 meters and 5 meters respectively .find the area of that rectangle.

Solution:

Area = l x w square unit
           
Given: Length= 10 meters
                        Breadth=5 meters
                                    =10x5
                        Area    = 50 m2      
     
4. The length and breadth of the rectangle are 11 feet and 6 feet respectively .find the area of   that rectangle

Solution:

Area = l x w square unit.
            Given: Length= 11feet
                        Breadth=6feet
                                    =11x 6
                        Area    = 66 ft2

Geometric area of Triangle


Area of the triangle is calculated by multiplying the base times the one-half the height.

Area of triangle= `(1)/(2)` (base x height)

Area = `(1)/(2)bh`

5. What is the area of triangle with base 5 and height 10 feet?

Solution:

Area = `(1)/(2)bh`

Given: Base= 5 feet.
         Heigh t= 10feet
                    = 1/2 (5x 10)
                    =1/2(50)

            Area =25 ft2

6. What is the area of triangle with base 7 and height 14 feet?
Solution:

Area = `(1)/(2)bh`

Given: Base= 7 feet.
         Height=14feet
                    =1/2 (7 x 14)
           Area =1/2 (98)
            Area =49 ft2

Geometric area of Circle

Area of the circle is calculated by multiplying pi ( π = 3.14) by the square of the radius
Area of the circle= π x r2

7. The radius(r) of a circle is 3 inches. Find the area of that circle?

Solution:

Area of the circle= π x r2
π=3.14

Given: r=3inches
          A=3.14 x (3)2
                   =3.14 x 9 inche2.
    Area= 28.26 in2.

8. The radius(r) of a circle is 7.5 meters. Find that area of the circle.

Solution:

Area of the circle is calculated by multiplying pi ( π = 3.14) by the square of the radius
Area of the circle= π x r2
π=3.14

Given: r= 7.5 meters
          A= 3.14 x (7.5)2
            =3.14 x 56.25
  Area =176.625 m2

Friday, March 1, 2013

circumference circle


In our real life, we could see many circular objects. For example, wheel of a vehicle, shape of a pizza, tennikoit ring,.. Take a rope or an inelastic thread and measure the circular path of the given object and that forms the circumference of the circular object. As the size of the circle increases, the circumference of circle also increases.

Introduction on circumference of a circle:

Circle is one of the most important shapes in geometry. Circumference is defined as the measure needed to make the closed curve. Circle has a fixed center. Distance between the center and a point on the circumference of the circle is called as radius. A line passing through center and any two points on the circumference of the circle is called as diameter.  If the radius or diameter is given then we can easily calculate the circumference of the circle. This article helps us to find the circumference of the circle with the given details.


Circumference of a circle:


The diagram below shows the circumference of circle.

Circumference of circle

The Circumference of a circle can be calculated using the following formula:

Circumference = 2  `pi`r  or `pi`

where r ----> radius of circle

d ----> diameter of circle

π---- > constant and value of π is  3.14 or 22/7

Diameter is twice the radius. So d = 2r and   r = `d/2`


Problems on finding circumference of the circle:

Ex 1: Find the Circumference of the circle with radius 20 cm.

Sol:

Step 1: Write the formula

Circumference of a circle  = 2  `pi`r units

Step 2: Plug the known values and calculate circumference

2π r               = 2 (22/7) 20

= 2 (3.14) 20

= 125.6 cm

Ex 2: Find the Circumference of the circle with radius 32 cm.

Sol:

Step 1: Formula for Circumference of a Circle

Circumference of a circle  = 2  `pi`r units

Step 2: Plug the known values and calculate circumference

2πr                  = 2 (22/7) 32

= 2 (3.14) 32

= 200.96 cm

Ex 3: Find the Circumference of the circle with diameter 52 in.

Sol:

Step 1: Write the formula

Circumference of a circle  = `pi` d

Step 2: Plug the known values and calculate circumference

πd             = (22/7) 52

= (3.14) 52

= 163.28 in

Ex 4: Find the Circumference of the circle with diameter 74 in.

Sol:

Step 1: Write the formula

Circumference of a circle  = `pi` d

Step 2: Plug the known values and calculate circumference

πd            = (22/7) 74

= (3.14) 74

= 232.36 in

I like to share this jee main 2013 sample paper with you all through my article.


Practice problems on circumference of the circle:


Find the Circumference of the circle with radius 18 cm. .
Answer: 113.04 cm

Find the Circumference of the circle with radius 28 cm.
Answer: 175.84 cm

Find the Circumference of the circle with diameter 63 in.
Answer: 197.82 in

Find the Circumference of the circle with diameter 81 in.
Answer: 254.34 in

Thursday, February 28, 2013

Different Number Combinations


In combinatorial mathematics, a k-combination of a finite set S is a subset of k different numbers of S. Specifying a subset does not arrange them in a particular order; by contrast, producing the k different numbers in a specific order defines a sequence without repetition, also called k-permutation (but which is not a permutation of S in the usual sense of that term. SOURCE: WIKIPEDIA



Example problems of different number combinations:

Different number combinations example 1:

How many lines can you draw using THREE non collinear (not in a single line) points X, Y and Z on a plane?

Solution:

You need two points to draw a line. The order is not important. Line XY is the same as line YX. The problem is to select TWO points out of THREE to draw different lines. If we proceed as we did with permutations, we get the following pairs of points to draw lines.

XY, XZ

YX, YZ

ZX, ZY

There is a problem: line XY is the same as line YX, same for lines XZ and ZX and YZ and ZY.

The lines are: XY, YZ and XZ; three lines only.

So in fact we can draw THREE lines and not SIX and that's because in this problem the order of the points X, Y and Z is not important.

This is a combination problem: combining TWO items out of THREE and is written the general form as follows:

n C r = n! / [ (n - r)! r! ]

Special case:

n C 0 = n C n = 1

The number of combinations (nCr) is equal to the number of permutations divided by r! to removes those counted more than once because the order is not mainly use.

Different number combinations example 2:

Calculate 4C3

Solution:

We can find the combination value by using the following formula:

n C r = n! / [(n - r)! r!]

Substitute the value of n and r into the above formula, then we get

4C3= 4! / [(4-3)! 3!]

=4! / [1!*3!]

=24/[1*6]

=24/6

=4

Answer: 4

Different number combinations example 3:

Calculate 6C6

Solution:

We can find the combination value by using the following formula:

n C r = n! / [(n - r)! r!]

Substitute the value of n and r into the above formula, then we get

6C6= 6! / [(6-6)! 6!]

=6! / [0!*6!]

=6! / [1*(6!)]

=6! / 6!

= 1

Answer: 1

Having problem with Probability Sets Read my upcoming post, i will try to help you.

Practice problems of different number combinations:


1) In how many ways can you select a committee of 2 students out of 5 students?

Answer: 20 (5C2)

2)  How many triangles can you make using 4 non collinear points on a plane?

Answer: 24 (4C3)

Wednesday, February 27, 2013

Learn Area of a Rhombus


Rhombus is a quadrilateral in which all the sides are equal. Rhombus has all the properties of a parallelogram and its diagonals bisect each other at right angles. The area of a rhombus can be calculated using the conventional formula used to calculate the area of a parallelogram b*h where "b" is the base and "h" is the perpendicular distance between the base and the opposite parallel line.

Rhombus

ABCD is a rhombus and we shall derive the formula for finding out the area given its diagonals AC and BD


learning how to find area of a rhombus


Let the length AC be d1 and that of BD be d2. The formula for calculating the area of a triangle is 1/2 bh where 'b" is the base and "h" is height or altitude.

We shall consider the rhombus as the combinations of two triangles ABC and ADC.If we add the areas of triangles ABC and ADC we are sure to get the area of the rhombus ABCD.

The diagonals of rhombus bisect each other at right angles the height of triangles of ABC and ADC will be half of the diagonal BD which is equal to d2/2. We shall now calculate the area separately and add.


Formula to learn area of a rhombus


Area of triangle ABC =1/2  (d1* d2/ 2) =(d1 d2) /4

Area of triangle ADC=1/2  (d1* d2/ 2) =(d1 d2) /4

Area ABC +Area ADC = (d1 d2 )/4 + (d1 d2 ) /4 =d1 d2 /2

The area of the rhombus  = 1/2 product of its diagonals

I like to share this algebra 2 formulas list with you all through my article.

learn examples on area of a rhombus


We shall illustrate this by two examples. We are given the diagonals of a rhombus as 10 cms and 12 cms. We are asked to find the area of the rhombus. The area of a rhombus= 1/2 the product of its diagonals= 1/2 *10*12 = 60 square cm.

This is an example to find the area of the rhombus using the conventional formula. Suppose the length of the side of a rhombus is given as 12cm and the perpendicular distance between the sides is given as 10 cm the area of the rhombus =side* perpendicular distance = 10 * 12 =120square cm.

Tuesday, February 26, 2013

Rational Algebraic Expressions


A rational expression is an algebraic expression of the `(P)/(Q)` from ,where P and Q are simpler expressions (usually polynomials), and the denominator Q is not zero.



This rational expressions whose numerators and denominators are (or written as) polynomials. Like polynomials, rational expressions appear frequently in the Algebra II and higher mathematics. We must understand the how to perform basic operations with rational expressions and how to solve rational equations.


Two Types:-


1.Adding and Subtracting Rational Expressions

2.Multiplying and Dividing Rational Expressions



1. Adding and Subtracting Rational Expressions

Adding Subtracting Rational Expressions with the Like Denominators

Add and subtract their numerators and then write the results over the denominator. Then, simplify the numerator factor, and write the expression in lowest terms.

Adding and Subtracting Rational Expressions with the Unlike Denominators

Rational expressions can be added and subtracted if and only if they have the same denominator. Thus, we must rewrite them as expressions with a common denominator.



2.Multiplying and Dividing Rational Expressions

Multiplying Rational Expressions

To multiply two rational expressions, factor them. Then multiply their numerators and denominators, crossing out the any factors that appear in both the numerator and the denominator

Dividing Rational Expressions

To divide by rational expression,and multiply by its reciprocal.


Examples:-


Example 1:

Simplify the rational expression

4x - 2
--------
2x - 1
Solution :-

Factor both the numerator and denominator completely.

2(2x - 1)
---------
2x - 1
Cancel common factors to reduce and then simplify the given expression.

2(2x - 1)
= ------------ = 2 , with x not equal to 1
2x - 1


Example 2:

Simplify the rational expression

4x + 16
---------
x2 - 16
Solution:-

Factor both the numerator and denominator completely.

4x + 16         4(x + 4)
--------- = ----------------
x2  - 16      (x + 4)(x - 4)
Cancel common factors to simplify the expression.

4(x + 4)
= ---------------
(x - 4)(x + 4)


4
= --------    , with x not equal to -4.
(x - 4)

I like to share this What is Rational Number with you all through my article.

Example 3:

Simplify the rational expression

x2 + x - 2
-------------
-x2 -2x + 3

Solution:-

Factor both the numerator and denominator completely.

x2 + x - 2      (x + 2)(x - 1)
------------- = ----------------
-x2 -2x + 3      (x + 3)(-x + 1)


Note that - x + 1 = - (x - 1) in the denominator.

(x + 2)(x - 1)
= -----------------
-(x + 3)(x - 1)


Cancel common factors.

(x + 2)(x - 1)
=--------------------
-(x + 3)(x - 1)


(x + 2)
= -------------   , with x not equal to 1
(x + 3)

Monday, February 25, 2013

Learning Compound Interest


Compound interest is paid on the principal and also for the interest accumulated in the past years. Compound interest emerges when interest is added to the principal, so the interest that has been added also earns interest. This adding of interest with the principal is said to be compounding. Compounding can be done for a time like yearly, quarterly, monthly, daily etc.


Learning Compound Interest Formula:


Learning The basic formula for Compound Interest is:

FV = PV (1+r)n

PV is the present value

r is the annual rate of interest (percentage)

n is the number of years the amount is deposit or borrowed for.

FV = Future Value is the amount of money accumulate after n years, including interest.

Learning Frequent Compounding of Interest:

If interest is paid more frequently, Here are a few examples of the formula:

Annually = P × (1 + r) = (annual compounding)

Quarterly = P (1 + r/4)4 = (quarterly compounding)

Monthly = P (1 + r/12)12 = (monthly compounding)

Learning Find the Present Value when know a Future Value, the Interest Rate and number of Periods.

PV = FV / (1+r)n

Learning Find the Interest Rate when know the Present Value, Future Value and number of Periods.

r = ( FV / PV )1/n – 1

Learning Find the number of Periods when know the Present Value, Future Value and Interest Rate

n = ln(FV / PV) / ln(1 + r)

I like to share this mathematical induction with you all through my article.


Example of compound interest


Ex 1: I have $1000.00 to invest for 3 years at rate of 6% compound interest.

Sol:  Here p=$1000, n=3, r=5

A = 1000 (1 + 0.06)3 = $1191.02.

1000.00 is worth $1191.02

Ex 2:  How many years to turns 1000into10,000 at 5% interest?

Sol :    n = ln( 10000 / 1,000 ) / ln( 1 + 0.05 ) = ln(10)/ln(1.05) = 2.3026/0.04879 = 47.19

Ex 3 :  I have $2000.00 to invest for 3 years at rate of 7% compound interest.

Here p=$2000, n=3, r=7

A = 2000 (1 + 0.07)3 = $2450.09.

2000.00 is worth $2450.09.

Friday, February 22, 2013

Angle of Elevation Learning


Introduction:

Assume that you are walking on a road. Normally your eyes will be viewing objects at a horizontal level at a distance of your height from the ground. Suppose you see a tall building in the vicinity and you want to see the top of the building. What you do is, rotate your line of sight from horizon to spot the top of thr building. The angle by which you do that is called the Angle of Elevation.

The angle of elevation and depression are a wonderful concepts in the subject of trigonometry.


Angle of elevation and depression- Definition
angle of elevation

Let AB be an object. The angle θ that is required to see the point A from point O is called the angle of elevation of the object at point O.

The angle of elevation of an object depends on the point from where it is measured. The more you are closer to the object, the more is the angle of elevation and vice versa.

Hence, it is a must that the angle of elevation of an object should always be accompanied by the information from where it is measured.

Angle of Depression is the angle by which you tilt your eye down from horizontal line to see an object which is below you.
Angle Of Depression

Angle of elevation – Practical applications

The concept of angle of elevation and depression is used very widely in estimations of heights and depths. In fact, in trigonometry, a separate topic heights and distances deals with angle of elevation and angle of depression. The angle of depression is the angle made below the horizon for objects at lower levels.
 angle of elevation of a building


Suppose the height of the building shown in the above picture (h) is to be estimated. It may not be practicable to measure that directly. But it is always possible to measure the angle of elevation θ (equipment for such equipment is available) and also the horizontal distance between the building and the point of angle measurement (d).

The basic trigonometric identity, tan θ =`(h)/(d)`, will easily give you the estimate.


Problems based on Angle of elevation and angle of depression


Let us do a  problems relating to angle of elevation and angle of depression to understand the concept properly.

Angle of Elevation Problems :
elevation
1)  A balloon is flying high. A boy looks at it. His eyes make an angle of 30 º from the ground to the balloon.

This is angle of elevation. The distance between the boy and  the flying balloon is 10 m. Find the height of the balloon above the Ground.

Here we use sine 30º formula =  opposite side / hypotenuse   = height / hypotenuse

Sine 30º= 1/2     hypotenuse = 10 m

so height = sine 30º x 10  =    `(1)/(2)` x 10m =  5 meter

So the ballon flies at a height of 5 meter above the ground

Problems based on Angle of depression

Problem 2)From the top of a light house, the angle of depression of 2 ships on the opposite side of the light house  are

observed as  45º and 3 angle 0º. The height of the light house is 200 m. Find the distance between the ships.
2 ships

Let  M be  a ship and N be another ship.   Let AB be the light house

CD is a line drawn horizontally through B.

From B  the angle of depression is 45º and 30º.

CD is parallel to MN

So angle CBM= angle BMA and angle DBN = angle BNA.

That makes angle BMA=45º and angle BNA= 30 degrees(Interior alternate angles  are equal)

In the right triangle BAN ,  tan 30º = AB/AN

Tan 30º= `(1)/(sqrt(3))`        So `(1)/(sqrt(3))`  = `(200)/(AN)`

So AN =  200√3 = 200 x 1.732 = 346.4 m

Now let us measure AM

Tan 45º = 1   Tan 45º = `(AB)/(AM)`  so AM x 1 = AB   AM= AB   AB= 200m so AM = 200 m

Distance between Ship M and the light house is 200m

Distance between ship N and the light house is 346.4 m

Add them both.

Distance between ship M and N is 200+346.4 = 546.4 meters
Having problem with ntse 2013 Read my upcoming post, i will try to help you.

Thursday, February 21, 2013

Probability Problems with Dice Eighth Grade



Probability is the chance that something will happen - how likely it is that some event will happen.If a trial will produce N commonly exclusive and equally probable outcomes out of which n outcomes are positive to the amount of event A, then the probability of A is mentioned by P(A) and is defined as the ratio n/ N. Thus the probability of A is given by


                                           Event (P)   = Number of Successful outcomes
                                                                   Number of total outcomes


probability problems with dice eighth grade

probability problem with dice for 8th grade:


Problem:

A fair die is thrown. Find the probabilities that the face on the die Is 

 (1) Maximum (2) Prime (3) Multiple of 3 (4) Multiple of 7

Solution:
            In the above probability problem there are 6 possible outcomes when a die is tossed. We assumed that all the 6 faces are equally likely. The classical definition of probability is to be applied here
            
The sample space is ,S={1,2,3,4,5,6}  => n(S)=6

(1) Let A be the event that the face is maximum
            Thus,
                       A=(6),        n(A)=1
            Therefore, P(A) = n(A) / n(S)
                                  = 1/6

(2) Let B be the event that the face is prime
            Thus,
                       B=(2,3,5)        n(B)=3   
            Therefore, P(B) = n(B) / n(S)
                                  = 3/6
                                  => 1/2

(3) Let C be the event that the face is multiple of 3
            Thus,          C=(3,6)    n(C)=2
          Therefore, P(C) = n(C) / n(S)
                                = 2/6
                                =>1/3

(4) Let D be the event that the face is multiple of 7
            Thus,          D  =0,           n(D)=0
           Therefore,P(D)  = n(D)/n(S)
                                  =0/6
                                  =0   (not possible)


Having problem with Probability Set Read my upcoming post, i will try to help you.

Dice problem for 8th grade:


Example:

Solve the problem for probability that when 2 standard 6-sided dice are rolled, the sum of the numbers on the top faces is 4.

Solution:

In the above problem, A dice contains 6 faces, so the possible out comes from the  both dices are      
                            = 6 * 6 
                            = 36 total number of possible outcomes 
Here the given condition is “Some of the numbers on the top of the face is 4”.
So the possible out comes are 
                   Dice 1             Dice 2
                      1         +         3           = 4
                      2         +         2           = 4
                      3         +         1           = 4
the total number of successful outcomes are 3

Final solution 
                          P (sum of 4)     = 3 / 36
                                                 = 1 / 12.

Wednesday, February 20, 2013

Volume of a Cylinder


Volume of a cylinder is a measurement of the occupied units of a cylinder. The volume of a cylinder is represented by cubic units like cubic centimeter, cubic millimeter and so on. Volume of a cylinder is the number of units used to fill a cube.

A cylinder has two parallel faces in its structure. The height of a cylinder is perpendicular to the two bases. The cylinder has a round base and a perpendicular height.



The volume of a cylinder formula depends on the area of the cylinder. The formula for volume of a cylinder can be written as,

Volume of cylinder = pi * r2 * h.


Formula for Surface Area of a Cylinder


The formula for volume of a cylinder depends on the area of the cylinder. The area of a cylinder can be written as, A = pi * r2. Here, pi is the constant value and r is the radius of the cylinder. To find the volume of the cylinder, we have to multiply the height of the cylinder to the area of the cylinder. The volume of cylinder formula can be written as,

Volume of cylinder = pi * r2 * h.

Here, pi is the constant variable, r is the radius of the cylinder and h is the height of the cylinder. The constant variable pi is equal to (22 / 7) or 3.14.


How to Find The Volume of a Cylinder


Given below are some of the examples to find the volume of a cylinder.

Example 1:

Calculate volume of a cylinder having the radius of cylinder is 3cm and height is 4cm.

Solution:

The given radius of the cylinder is 3cm and height of the cylinder is 4cm

Formula:

Volume of a cylinder = pi * r2 * Height

Volume of cylinder = 3.14 * 32 * 4 cm3

= 113.04 cm3

Answer:

The volume of cylinder is 113. 04 cm3

Having problem with hard math problems for 7th graders Read my upcoming post, i will try to help you.

Example 2:

The radius and height of the cylinder is 5 cm, 21 cm. Find the volume of cylinder.

Solution:

Given radius r = 5 cm, height = 21 cm.

Formula:

Volume of cylinder = pi * r2 * h

= 3.14 * 52 * 21 cm3

= 1648.5 cm3

Answer:

The volume of given cylinder is 1648.5 cm3

Example 3:

Find the volume of cylinder for the given base and height. base = 6 cm and height = 4 cm

Solution:

Given base = 6 cm and height = 4 cm

Formula:

Volume of cylinder = pi * r2 * h

= 3. 14 * 62 * 4 cm3

= 452.16 cm3

Answer:

The volume of cylinder is 452.16 cm3
I like to share this Surface Area of a Cylinder Calculator with you all through my article.