Does this picture show the diameter or radius of a circle?

Suppose that the price p (in dollars) and the weekly sales x (in thousands of units) of a certain commodity satisfy the demand equation 4p cubedplusx squaredequals38 comma 400. determine the rate at which sales are changing at a time when xequals80, pequals20, and the price is falling at the rate of $.20 per week.

Find the area of a parallelogram with base 15 yards and height 21 2/3

1yd 1 ft = 1 1/12 1 1/3 1 1/2 1 1/6