Find the unknown measurement for the fugure

Area is b×h/2 52.5=5×h/2 multiply both sides by 2 105=5h Divide both.sides by 5 21=h

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