What is the value of model below ?

Rectangle pqrs has length a and width 4b. the x-axis bisects ps and qr what are the coordinates of the vertices

The probability that a student graduating from suburban state university has student loans to pay off after graduation is .60. if two students are randomly selected from this university, what is the probability that neither of them has student loans to pay off after graduation?

Find the missing dimension! need asap! tiny square is a =3025 in ²