80 would be your answer for this question
The formula for the area of a circle is

We know the diameter, and the radius is half of the diameter. So the radius is 9. Now we plug that into the formula.

So the answer is B, 81 pi square feet
Answer:
The estimated sum is ≈10
Step-by-step explanation:
This depends on how your professor wants you to estimate sums. Logically, though, a value of nearly 4 and a value of just over 6 add to about 10. The exact answer would be a bit over 10, at ≈10.14117
Okay so first, area is length times width, so 1/4x*x would be first = 1/4(x^2)=64. Then area or x = 16 or -16
perimeter would be width times two plus length times two. I recommend using math papa to calculate these numbers.