Answer:
100 π
Step-by-step explanation:
Since the equation for the area of a circle is π r^2, and the diameter is 20m. There is enough info to proceed.
First, half the 20m to 10m since the radius is 1/2 of the diameter.
Next, plug this into the formula to get the answer:
π 10^2
π 100
100 π is the answer, since it is looking for it in terms of π.