Question

Find the circumference of the circle when given the diameter of 42cm. Write the formula for circumference and explain in detail how you arrived at your answer. Keep in mind the diameter is 42cm. You must find the radius in order to solve for the circumference.

Answer 1

132 cm

Explanation:

The diameter of the circle is 42 cm. A circle's radius is half of its diameter, hence, its radius is:

42 / 2 = 21 cm

The circumference of a circle is the total length of the circle and it is given as:

`C = 2\pi r`

where
`\pi = \frac {22} {7}`

r = radius of the circle

Hence, the circumference of the circle is:

`C = 2 * \pi * 21\\C = 132 cm`