Question

A cake has CIRCUMFERENCE of 20.41 inches. What is the AREA of the cake? Use 3.14 to approximate n. Round to the nearest tenth, but enter it without a label. Enter your answer in the box.

Answer 1

Circumference of a circle is

`P=2*\pi* r`

where r is the radius, and P the value of circunference or perimeter, then replace P and pi to solve r

`\begin{gathered} 20.41=2*3.14* r \\ 20.41=6.28r \\ (20.41)/(6.28)=(6.28)/(6.28)r \\ \\ 3.25=r \end{gathered}`

radius is 3.25 inches

Area

Apply formula of the area of a circle

`A=\pi* r^2`

repalce pi and r to find the area

`\begin{gathered} A=3.14*(3.25)^2 \\ A=3.14*10.5625 \\ A=33.16625 \end{gathered}`

The rounded value of the area is 33.2 square inches