Online Geometry Problem 808: Parallelogram, Perpendicular, Right Triangle, Semicircle Area, Diameter. Level: High School,
SAT Prep, College,
Mathematics Education

The figure below shows a parallelogram ABCD,
DE perpendicular to AB and semicircles of diameters AE, BC and DE. If S_{1}, S_{2},
and S are the areas of the shaded regions, prove that S_{1}+ S_{2} =S