Question

4. A circle has a radius of 2 cm. a. Find the exact area of the circular region.b Find the approximate area using 3.14 to approximate it.

Answer 1

The formula for the area of circle is,

$A=\pi(r)^2$

Substitute 2 for r in the formula to obtain the area of circle.

$\begin{gathered} A=\pi(2)^2 \\ =12.56637061 \end{gathered}$

So, exact area of circle is 1.56637061 square centimeter.

Substitute 2 for r and 3.14 for

$\pi$

in the formula to obtain the approximate area of circle.

$\begin{gathered} A=3.14\cdot(2)^2 \\ =12.56 \end{gathered}$

So approximate area of circle is 12.56 square centimeter.