Question

The diameter of a quarter is 2.5 cm. What is it’s circumference?

Answer 1

7.85 cm

Explanation:

The circumference of a circle can be found using the following formula.

`c=\pi d`

The diameter is 2.5 centimeters. Therefore, we can substitute 2.5 cm in for d.

`c=\pi *2.5 cm`

Now, find the circumference.

- In terms of pi:

`c=\pi *2.5 cm`

`c= (2.5)\pi cm`

`c= 2.5\pi cm`

-Using 3.14 as pi

`c=\pi *2.5 cm`

`c=3.14 *2.5 cm`

`c=7.85 cm`

-Using 3.14159... as pi

`c=\pi *2.5 cm`

`c=7.85398163 cm`