Find the area of the shaded regions below. Give your answer as a completely simplified exact value in terms of π (no approximations).

In the diagram, the ratio of ab to ae is (1/2) . what is the ratio of the length of to the length of ?

Find the area of a parallelogram with base 15 yards and height 21 2/3

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.