Problema Solution

The height of a triangle is 4 inches greater than twice its base. The area of the triangle is 168 square inches. What is the base of the triangle?

Answer provided by our tutors

Area of a triangle is 1/2 * base * height. In this case, you know area = 168 and height = 2*base + 4,so you write two equations using variables as follows:

A = area, b = base, h = height

A = 168 = 1/2 * b * h

h = 2b + 4

substitute the second equation into the first

168 = 1/2 * b * (2b + 4)

168 = b^2 + 2b

b^2 + 2b -168 = 0

(b-12)(b+14) = 0

b = 12 (or -14, but -14 not allowed)

Answer is c, b= 12in.