How would this quadrilateral be best classified, and what is the measure of Angle B?

What is the average rate of change for this function for the interval from x=2 to x=4 ?

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?

Find the measure for the angle indicated in bold