The diameter of a circle is 18 m. Find its area in terms of piπ.
The formula for finding the area of a circle is A = πr^2, where r is the radius of the circle.
Since the diameter is twice the length of the radius, we can find the radius by dividing the diameter by 2:
radius = 18m / 2 = 9m
Therefore, the area of the circle is:
A = π(9m)^2
A = π(81m^2)
A = 81π m^2
So, the area of the circle is 81π square meters.