Question

find the circumference (in cm) of the circle. use $piapprox\frac{22}{7}$.

Explanation:

Step1: Identify radius

The diameter $d = 42$ cm. The radius $r=\frac{d}{2}=\frac{42}{2}=21$ cm.

Step2: Use circumference formula

The formula for the circumference of a circle is $C = 2\pi r$. Substitute $r = 21$ cm and $\pi=\frac{22}{7}$ into the formula.
$C=2\times\frac{22}{7}\times21$.
First, $2\times21 = 42$, then $42\times\frac{22}{7}=\frac{42\times22}{7}=132$ cm.

Answer:

132