Question 444877: The altitude of a triangle is 5 m less than its base. The area of the triangle is 42 m2. Find the length of the base. Answer by nerdybill(7384) (Show Source):
You can put this solution on YOUR website! The altitude of a triangle is 5 m less than its base. The area of the triangle is 42 m2. Find the length of the base.
.
Let b = base
then
b-5 = altitude
.
since we know that the area for any triangle is
(1/2)bh
where
b is base
h is height or altitude
.
(1/2)b(b-5) = 42
b(b-5) = 84
b^2-5b = 84
b^2-5b-84 = 0
(b-12)(b+7) = 0
b = {12, -7}
toss out the negative solution leaving:
b = 12 meters
