Oct 15, 2024

OK, add a line segment, length x, from the upper left corner of the square to the lower left end of the semicircle. x^2+3^2=4^2, or x=sqrt(7). Now, h/x=3/4, or h^2=9x^2/16=63/16, the area is about 3.94. (The semicircle area is about 6.28.)