SOLUTION: I have a problem that doesn't make sense to me. If someone could help me I would really appreciate it. the question: The base of a triangle is 5cm greater then the height. The

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I have a problem that doesn't make sense to me. If someone could help me I would really appreciate it. the question: The base of a triangle is 5cm greater then the height. The       Log On


   

Question 507537: I have a problem that doesn't make sense to me. If someone could help me I would really appreciate it.
the question:
The base of a triangle is 5cm greater then the height. The are is 18cmsq. Find the height and length of the base.
so the base is
h+5
height is
h
area=18
Please help!
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Start with the formula for the area of a triangle:
A+=+%281%2F2%29b%2Ah Now substitute A = 18, b = h+5
18+=+%281%2F2%29%28h%2B5%29%2Ah Multiply both sides by 2.
36+=+h%5E2%2B5h Rewrite this as:
h%5E2%2B5h-36+=+0 Solve by factoring.
%28h%2B9%29%28h-4%29+=+0 Apply the zero product rule.
h%2B9+=+0 or h-4+=+0 so...
h+=+-9 or h+=+4 Discard the negative solution as the height, h, can only be positive.
So the height is 4 cm. and the base 4+5 = 9 cm.