How is 10+10 the same as 11+11?

How can we find the measure of an exterior angle if we know the measurement of an interior angle

Aswimming pool is a rectangle with semicircles on the end. the rectangle is 12 meters wide and 30 meters long. the diameter and width of the swimming pool are equal. sketch and label an overhead diagram of the swimming pool. find the area of the swimming pool floor.

Find the solution of each of the following.