How do you compare y intercepts and rates of change

Using d, e, and f as values on a triangle and d being 60 degrees, what is the value of e and f if d is 60 degrees? also, what do you notice about the values of e and f?

What is the rate of change of a line that passes through (2,-5) and (6,-2)?

Find the maximum value of p= 4x + 5y subject to the following constraints :