The base of a triangle is 18 inches longer than twice the length of its​ altitude, x. Write a polynomial that represents the area of the triangle?

word problem

1 Answer
Oct 19, 2017

#x^2+9x#

Explanation:

From above information.

Let the altitude of the triangle be #x#.

We know that the base is twice this plus 18.

So base length is:

#2x +18#

Area of a triangle is #1/2# base x height.

So:

#1/2(2x+18)*x#

Expanding this:

#1/2(2x^2+18x)= x^2+9x#