Answer:
The area of the shaded region is 7π square centimeters.
Step-by-step explanation:
Note that Circle B has a radius of 3 cm, and the two smaller circles, Circles O and C, both have a radius of 1 cm.
The area of a circle is given by:

Therefore, the area of Circle B, the entire circle, is:

The area of Circle O is:

And likewise, the area of Circle C is:

The area of the shaded area is the area of the Circle B subtracted by the area of Circles O and C. Hence:

Substitute and evaluate:

The area of the shaded region is 7π square centimeters.
The first answer is A because (b+6) represents the sidewalk length. (With the pool length and the two corners, which equal 3 ft each.) Then, the sidewalk width would be (h+6) for the same reason. Multiply them and get the pool area plus the sidewalk area. But you only need the sidewalk area so you would subtract the pool area from the whole area, to get (b+6)(h+6)-bh, or A in the end.
Unfortunately, I do not know the answers to the rest of the problems. I still hope this helped though!
I think Deal B correct me if im wrong..
Here you go! Hope this helps!