Question

what is the area of a circular region whose diameter is 6 centimeters?
a 6π cm
b 9π cm
c 12π square cm
d 9π square cm

Explanation:

Step1: Find the radius

The radius \(r\) of a circle is half of the diameter \(d\). Given \(d = 6\) cm, so \(r=\frac{d}{2}=\frac{6}{2}=3\) cm.

Step2: Use the area formula

The area formula of a circle is \(A=\pi r^{2}\). Substitute \(r = 3\) into the formula: \(A=\pi\times3^{2}=\pi\times9 = 9\pi\) square cm.

Answer:

D. \(9\pi\) square cm