HINTS

 

As an alternative approach consider this:

 

 

Or perhaps one of these figures is more intuitive:

 

          

 

In the figure above to the right, the area of the circle with diameter DB is twice the area of the circle with diameter AB.   So the sum of the areas of the four semicircles on  AB, BE, ED, and DA would be the same as the area of the circle with diameter DB.

 


Return