Distance of a semicircle

Question

Find the distance around each semicircle. Use 22/7 as an approoximation for pi. The radius is 42cm.

Answer 1

This is a question about circumference, which is the distance around a circle. The formula for circumference is

C = 2πr, where r is the radius.

The circumference of a semi-circle would be half that, or C = πr.

Therefore, for this semi-circle:

C = 22/7(42)

Since 7 goes into 42 six times, this problem becomes C = 22 * 6 = 132 cm