Question

a circle has an area of approximately 28.27 square centimeters. which measurement is closest to the radius of the circle in centimeters?
a 9 cm
b 5 cm
c 6 cm
d 3 cm

Explanation:

Step1: Recall area formula

The area formula of a circle is $A = \pi r^{2}$, where $A$ is the area and $r$ is the radius.

Step2: Solve for radius

Given $A\approx28.27$, we have $28.27=\pi r^{2}$. Since $\pi\approx3.14$, then $r^{2}=\frac{28.27}{3.14} = 9$.

Step3: Find radius value

Taking the square - root of both sides, $r=\sqrt{9}=3$ (we consider the positive value since radius is non - negative).

Answer:

D. 3 cm