Question

HELP ME PLZZZ
The height of a triangle is 5m less than its base. The area of the triangle is 42m^2. What is the length of the base?
A: 42=x(x-5)
B: 42=1/2(x)(x-5)
C: 42=x^2-5
D: 42=1/2(x^2-5)

Answer 1

h = height of triangle
b = length of triangle base
A = area of triangle

Recall the formula for area of a triangle :

A = 1/2 bh

Plug in what was given in the problem :

h = b - 5
A = 42

A = 1/2 bh
42 = 1/2 b (b-5) 

Answer 2

The answer would be B.