What do i need to know about geometry proofs on a test?

What is the area of the trapezoid shown ?

Which expression gives you the distance between the points (5,1)and(9,-6)

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?