math
posted by Sadie on .
The base of a triangle is 3 cm greater than the height. The area is 14cm^2. Find the length and height of the base.

The area of a triangle is
A = base * height /2
If you have not learned to solve quadratic equations before, then think of
2A = base * height
Since A=14, 2A = 28
Look for two integers that multiply together to give 28, but with a difference of 3 between them.
If you have learned quadratic equations, then let
h=height
b=base = h+3
Using the area formula above, you'll get
A=14 = h(h+3)/2
from which you can solve for the height h. The base is simply h+3. 
let the height be x cm
then the base is x+3 cm
x(x+3)/2 = 14
solve for x