Posted by Valentine on .
The base of a triangle is 8 cm greater than the height. The area is 64 cm^2. Find the height and the length of the base.

algebra 
Henry,
height = Xcm,
Base = (X + 8)cm,
A = bh/2 = (X + 8)X/2 = 64,
Multiply both sides by 2:
(X + 8)X = 128,
X^2 + 8X = 128,
X^2 + 8X  128 = 0,
(X  8)(X + 16) = 0,
X  8 = 0,
X = 8.
X + 16 = 0,
X = 16.
Use the + value of X:
X = 8cm = height.
X + 8 = 8 + 8 = 16cm = base.