The baseball field is in the shape of a square with a side length 90 feet.

Plate A player runs from the home plate at one corner, along the perimeter of the square, passing first- base, second-base, and then third-base at the other corners. Between the first and the second bases, the runner is moving at a constant rate of 20 feet per second. At what rate is the runner's distance L from home plate changing, 3 seconds after they leave first-base? Show and explain your work. Indicate clearly your choice of variables and your final answer Tir (rounded to the nearest hundredth)