Question

A circular mirror has a radius of 40 inches. Find the circumference to the nearest tenth of an inch.

Answer 1

To calculate the circumference, you can use the formula:

$C=2\pi r$

Where C is the circumference and r is the radius.

Then, you can follow the steps.

1. Substitute the radius in the equation.

In this exercise, r = 40 inches.

$\begin{gathered} C=2\pi40 \\ C=80\pi \end{gathered}$

2. To get the approximate result, use π= 3.14 and multiplicate it in the equation.

$\begin{gathered} C=80\cdot3.14 \\ C=251.2in^2 \end{gathered}$

Done! You found the circumference.

Answer: 251.2 in².