Question

Find the circumference and the area of a circle with radius 9 cm. Use the value 3.14 for n, and do not round your answers. Be sure to include the correct unit in you answers.

Answer 1

Given the figure, we can deduce the following information:

radius= 9 cm

To determine the circumference and the area of the circle, we use the following formulas:

Circumference:

$C=2\pi r$

Area:

$A=\pi r^2$

where:

C=Circumference

A=Area

r=radius=9 cm

π=3.14

Next, we solve for the circumference of the given cirle:

$\begin{gathered} C=2\pi r \\ C=2(3.14)(9) \\ Calculate \\ C=56.52\text{ }cm \end{gathered}$

Then, we get the area:

$\begin{gathered} A=\pi r^2 \\ A=(3.14)(9)^2 \\ Calculate \\ A=254.34\text{ }cm^2 \end{gathered}$

Therefore, the answers are:

$\begin{gathered} Circumference=56.52\text{ cm} \\ Area\text{ = 254.34 }cm^2 \end{gathered}$