Find the Area of a Circular Region That Has a Diameter

Multiple Choice

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