Calculate the area of a circle with a diameter of 18 m. Give an exact answer.
A- 81 n2 m2
B- 9 n m2
C- 18 n m2
D- 81 n m2
The formula to calculate the area of a circle is A = πr^2, where r is the radius of the circle. Since the diameter is given, we can find the radius by dividing the diameter by 2.
Radius = 18m / 2 = 9m
Now, we can plug the radius into the formula:
A = π(9m)^2
A = 81π m^2
So the exact area of the circle is 81π m^2.
Therefore, the correct answer is not listed in the options provided.