The formula of an area of a circle with radius r:

Part A.
We have diameter of the circle d = 8 in. The diameter of a circle is equal two times length of a radius.
Therefore:

Calculate the area:

Answer: C. 16π square inches.
Part 2.
Look at the picture.
Total area:

Answer: C. 36π square inches
Answer:
Step-by-step explanation:
what's the question exactly?
Answer:
11,040 is the answer
Step-by-step explanation:
you just need to subtract
Answer:

Step-by-step explanation:
I am assuming that you mean (4,−9) and (8, -3).

Hope this helps.