Answer:
If r = 18, the area of the circle is 1017.88
If d = 18, the area of the circle is 254.47
Step-by-step explanation:
Because your question was a little vague I had to give two answers. You need to specify what 18 is; is it the radius or the diameter?
Since the equation for finding the area of a circle is A = 2 * π * r, and half of the diameter of a circle is equal to the radius, the answers will be quite different.
If radius:
r = 18
A = 2 * π * (18)
A = 1017.88
If diameter:
d=18
1/2 * 18 = 9
A = 2 * π * (9)
A = 254.47
