Question

Given the triangle that has a base of five less than triple the height. The height is 2x+6.

Part A: Determine the expression that represents that area of the triangle.

Answer 1

A = 0.5(2x+6)(6x+13) = 6x² + 49x + 78

Explanation:

H = 2x+6 - the hight

3H = 3(2x+6) - triple the hight

3H-5 = 3(2x+6) - 5 - five less than triple the height

Area of triangle: A = 0.5BH

B = 3(2x+6)-5 = 6x + 18 - 5 = 6x + 13

H = 2x+6

So:

A = 0.5(2x+6)(6x+13) = (x+6)(6x+13) = 6x² + 13x + 36x + 78

A = 6x² + 49x + 78