Find the area of a circular region that has a diameter of 3 yards. Express the answer in terms of $\pi$ .
A) $9 \pi \mathrm { yd } ^ { 2 }$
B) $\frac { 9 } { 4 } \mathrm { yd } ^ { 2 }$
C) $\frac { 9 } { 4 } \pi \mathrm { yd } ^ { 2 }$
D) $\frac { 9 } { 2 } \pi \mathrm { yd } ^ { 2 }$
E) none of these

Question

Quizplus · Accepted Answer

The radius of the circle is half the diameter, which is 1.5 yards. The area of a circle is given by $A=\pi r^2$, so substituting in the radius, we get $A=\pi(1.5^2)=\frac{9}{4}\pi$ square yards. Therefore, the answer is C.

Find the Area of a Circular Region That Has a Diameter