Question 274701
the rectangle sits centered on the diameter with the upper corners touching the semicircle


two radii drawn to the upper corners divide the rectangle into three triangles


the area of one of the smaller outer triangles is equal to 1/4 of the area of the rectangle
(bisecting the larger central triangle shows the 4 smaller congruent triangles)


the hypotenuse of the triangle is the radius (10)
the height of the triangle is the height of the rectangle (h)


by Pythagoras, the base of the triangle is ___ sqrt(100 - h^2)


the area of the triangle is ___ (1/2) (h) (sqrt(100 - h^2))


the area of the rectangle is 4 times the triangle