Pls help me I will brainlest only part 4

Adecorative window is made up of a rectangle with semicircles at either end. the ratio of ad to ab is 3: 2 and ab is 30 inches. what is the ratio of the area of the rectangle to the combined area of the semicircles? possible answers: a. 2: 3 b. 3: 2 c. 6: π d. 9: π e. 30: π

Arock was dropped from the top of a building. the function that describes the height after it was dropped is f(x)=64-16x^2. what are the zeros of the function and what do they mean?

∠a and ∠ b are complementary. if m∠ b = 80°, what is the measure of ∠ a? 10° 80° 90° 100°