Whats the solution of y?

What is the measure of angle afe? 79 81 91 99

()1. how do you find range? 2.the following set of data is to be organized into a histogram. if there are to be five intervals on the graph, what should the length of each interval be? 30, 34, 23, 21, 27, 25, 29, 29, 25, 23, 32, 31

Ineed i been stuck on this question since yesterday