The height of a triangle is 5 m less than it's base. The area of the triangle is 42 m^2 what is the length of the base

12 meters

Step-by-step explanation:

Let b = base

then

b-5 = altitude

since we know that the area for any triangle is

(1/2) bh

where

b is base

h is height or altitude

(1/2) b (b-5) = 42

b (b-5) = 84

b^2-5b = 84

b^2-5b-84 = 0

(b-12) (b+7) = 0

b = {12, - 7}

toss out the negative solution leaving:

b = 12 meters

Here is the set up:

A = (bh) / 2

42 = [b • (b - 5) ]/2

This is all you need. Solve the equation for b to find your answer.