h is equal to 21. To find the area of a triangle, you need to use the formula 1/2 times base times height. So, 1/2 times h times 5 and this would be equal to the given area which is 52.5 Then after that, you just simplify the equation. 5/2h = 52.5 divide both sides by 2/5 to get h = 105/5 in order to get 21