Two shaded quarter-circles, each with a radius of 4 units, are formed in the 4 by 8 rectangular region shown. What is the area of the non-shaded region, in square units? Express the area in the form $a-b\pi$ where $a$ and $b$ are integers.
The area is 64 - 16*pi.
i got it, the answer is 32-8pi
Area of rectangle = 8*4 = 32
The two quarter circles make a half circle of radius 4, so Shaded area = (1/2)*pi*4^2 = 8pi
Hence non-shaded area = 32 - 8pi
