First draw sloping up (steep because he’s running)to the right until you hit 20 on the y axis. Next draw down and to the right for 5 yards until 15 on y axis. Next is a flat horizontal line for 3 seconds on x axis. Finally a shallow slope line down (because he is walking) and right until you hit the x axis.
A = L * W
A / L = W <==
when A = 42 and W = 16.8
A / L = W
42/16.8 = W
2.5 = W <=== width = 2.5 inches
hay that no solution because the root is irrational... and this is my answer