The answer is A. 179 ft^2.
If you can visualize it, they give us two circles and they want to know the area of the outer circle. So, we have to subtract the smaller circle from the bigger one to find the area of the walkway.
First, find the area of the big circle or the walkway. The formula for area of a circle is pi*radius^2.
Finding the radius is a little tricky. We have to add up the radius of the small circle to the radius of the outer circle.
To find a radius of the circle, divide the diameter by two. So, 16/2=8. 8 is the radius of the small circle. Now, add three to that to get the radius of the big circle.
8+3=11
Plug in the radius into the formula for area of a circle. They also state to use 3.14 for pi.
3.14*11^2 = 3.14*121 = 379.94
We now know the area of the big circle but we got to subtract this from the area of the small circle. We know the radius is 8. So, let's plug it in.
3.14*8^2 = 3.14*64 = 200.96
We can now subtract the big area from the small area and we will only be left with the area of the walkway.
379.94 - 200.96 = 178.98 ft^2. Approximate means close but not the exact answer, so round up to 179 ft^2. Hope this helped!
