4/15 Miles
The formula for the area of a parallelogram is A=b*h. We plug in the information that we know and solve for the missing height.

Multiply both sides by the reciprocal of 3/8 which is 8/3 so it is canceled on the right side.

multiply the factions to get 8/30. 8 and 30 have common factors of 2 and can reduce to 4/15