Area of 1/4 of a circle is (25/4)*pi

Area of triangle part of the piece is (1/2)*5*5

Area of upper part of piece is the difference between the two Areas= (25/4)pi -(25/2)

Area of one of the shaded parts is 2*[(25/4)pi -(25/2)] = 14.26

There are 16 such shaded parts so the total shaded area is 16 * 14.26 = 228.16

I'm glad we agree.