Question

Please help!!!! The height of a triangle is 9m less than its base. The area of the triangle is 56m^2. Find the length of the base.

Answer 1

Area = 1/2 b * h
h = b - 9
b = b
Area = 56cm^2

Area = 1/2 (b - 9) * b
56 = 1/2 (b^2 -9b)
112 = b^2 - 9b 
b^2 - 9b - 112 = 0
b = 16 and therefore the height is
h =  26 - 9 = 7

Check 
Area = 1/2 * 16 * 7
Area = 8 *7
Area = 56 which checks.