Question

What is the radius of a circle with circumferenceC= 40 CM

Answer 1

The circumference C, of a circle is;

`C=\pi r^2`

Given;

`C=40cm,\pi=3.14`

The radius r, is;

`\begin{gathered} 40=3.14(r^2) \\ \text{Divide both sides by 3.14} \\ (40)/(3.14)=(3.14(r^2))/(3.14) \\ r^2=12.74 \\ \text{Take the square root of both sides;} \\ \sqrt[]{r^2}=\sqrt[]{12.74} \\ r=3.57 \end{gathered}`

The radius of the circle is 3.57cm