well, what we do is, simply get the area of the containing rectangle, is an 8x10, and then get the area of the circle, with a radius of half of 4.3 or r = 2.15, and then if we subtract the area of the circle from the rectangle's, what's leftover is the shaded part.
[tex]\stackrel{\textit{\large Areas}}{\stackrel{rectangle's}{(8\cdot 10)}~~-~~\stackrel{circle's}{[\pi (2.15)^2]}}\implies 80-4.6225\pi ~~\approx~~65.5[/tex]
