posted by tmouery .
A swimming pool is in the form of a semicircular figure. Its width is 20 ft. and that parallel portions of the sides are each 20 ft. What is the are of a 5-ft-wide walk surrounding the pool? Round to the tenths.
what "sides" of a semicircle are parallel? Do you mean the circle has a diameter of 20 ft? If the base is 20 ft, then that would be the diameter of the circle.
Assuming that, we have a pool with area 1/2 pi * 10^2 = 50pi ft^2
Increase the radius by 5 ft, and you have an area of 1/2 pi * 15^2 = 225/2 pi
So, the area of the walk is 125/2 pi = 196.4 ft^2
If I have interpreted the dimensions incorrectly, fix my error and redo the calculation.