Question

what is the area of a circular region whose diameter is 12 centimeters?
a 36π square cm
b 36π cm
c 12π cm
d 24π square cm

Explanation:

Step1: Find the radius

The radius $r$ of a circle is half of the diameter $d$. Given $d = 12$ cm, so $r=\frac{d}{2}=\frac{12}{2}=6$ cm.

Step2: Calculate the area

The area formula of a circle is $A=\pi r^{2}$. Substitute $r = 6$ cm into the formula, we get $A=\pi\times6^{2}=36\pi$ square cm.

Answer:

A. 36$\pi$ square cm