Question 181919: The base of a triangle is 6 cm longer than its altitude. If the area of the triangle is 108 sq. cm, then what is the length of the base? Answer by nerdybill(7384) (Show Source):
You can put this solution on YOUR website! The base of a triangle is 6 cm longer than its altitude. If the area of the triangle is 108 sq. cm, then what is the length of the base?
.
Area for any triangle = (1/2)bh
where
b is length of base
h is length of height or altitude
.
Let x = altitude
then
x+6 = base
.
108 = (1/2)(x+6)(x)
216 = (x+6)(x)
216 = x^2+6x
0 = x^2+6x-216
0 = (x-12)(x+18)
.
x = {12, -18}
Throw out the negative solution leaving
x = 12 cm (altitude)
.
Base:
x+6 = 12+6 = 18 cm (length of base)
