Chapter SR18, Problem 1P

Solution

Find the circumference and area of the circle. Give an exact answer and an approximate answer for each.

The circumference of circle is $10\pi$ in. or about 31.4in.

The Area of circle is $25\pi in{.}^2$ or about $78.5i{n}^2.$

Given:

The given circle is −

  

Concept Used:

• Formula of circumference of circle $=2\pi r$
• Formula of Area of circle $=\pi r^2$

Calculation:

The given circle is −

  

Radius of given circle = 5in.

Circumference of circle $=2\pi r$

  $\begin{array}{l}=2\pi 5\\ =10\pi \\ =10(3.14)\\ =31.4\end{array}$

The circumference of circle is $10\pi$ in. or about 31.4in.

Area of circle $=\pi r^2$

  $\begin{array}{l}$ =\pi {(5)}^2$=25\pi \\ =25(3.14)\\ =78.5\end{array}$

The Area of circle is $25\pi in{.}^2$ or about $78.5i{n}^2.$