Your car's back window is in the shape of a trapezoid with the dimensions shown. The 1616-inch window wiper cleans a part of the window in a semicircular pattern. What is the approximate area of the window that is NOT cleaned by the wiper?
Semicircle area = circle area / 2 = (pir^2)/2
16 in is the radius. Let's call the area of this semicircle s.
3.1416^2=s
Trapezoid area = ((base 1 + base 2) / 2) h
Here, base 1 is 44 and base 2 is 36. The height (h) is 20. Let's call this trapezoid's area t.
(44+36)/2 20 = t
We can remove the area of the semicircle (that created by the windshield wiper) by subtracting it from the area of the trapezoid.
t - s = uncleaned area
[(44+36)/2 20] - [3.14 16^2] = uncleaned area