FINDING CIRCUMFERENCE OF A CIRCLE WORKSHEET

Problem 1 :

An irrigation sprinkler waters a circular region with a radius of 14 feet. Find the circumference of the region watered by the sprinkler.  Use 22/7 for π.

Problem 2 :

The diameter of a car wheel is 21 inches. Find the circumference of the wheel. 

Problem 3 :

The Ferris wheel shown makes 12 revolutions per ride. How far would someone travel during one ride ?

Detailed Answer Key

Problem 1 :

An irrigation sprinkler waters a circular region with a radius of 14 feet. Find the circumference of the region watered by the sprinkler.  Use 22/7 for π.

Solution : 

Use the formula. 

C  =  2πr

Plug 14 for r 

C  =  2π(14)

Plug 22/7 for π 

C  ≈  2 x (22/7) x 14

Simplify 

C  ≈  2 x (22/1) x 2

C  ≈  88

So, the circumference of the region watered by the sprinkler is about 88 feet.

Problem 2 :

The diameter of a car wheel is 21 inches. Find the circumference of the wheel. 

Solution : 

Radius  =  Diameter / 2 

Radius  =  21/2 inches

Use the formula. 

C  =  2πr

Plug  21/2 for r 

C  =  2π(21/2)

Plug 22/7 for π 

C  ≈  2 x (22/7) x (21/2)

Simplify 

C  ≈  2 x (11/1) x (3/1)

C  ≈  66

So, the circumference of the wheel is 66 inches.

Problem 3 :

The Ferris wheel shown makes 12 revolutions per ride. How far would someone travel during one ride ?

Solution : 

Distance traveled in one revolution is equal to circumference of the Ferris wheel.

Then the distance traveled in 12 revolutions is equal to 12 times circumference of the Ferris wheel.  

Let us find circumference of the Ferris wheel. 

Radius  =  Diameter / 2 

Radius  =  63/2 feet

Use the formula. 

C  =  2πr

Plug  63/2 for r 

C  =  2π(63/2)

Plug 22/7 for π 

C  ≈  2 x (22/7) x (63/2)

Simplify 

C  ≈  2 x (11/1) x (9/1)

C  ≈  198 feet

Distance traveled in one ride (12 revolutions) is 

=  12 x circumference

=  12 x 198

=  2376 feet

The distance traveled  during one ride is 2376 feet.

Kindly mail your feedback to v4formath@gmail.com

We always appreciate your feedback.