a triangle has an area of 35 square inches, and its base is 3 inches more than it's height. Find the base and height of the trianlge

1 answer

Area of a triangle:

A = b * h / 2

A triangle base is 3 inches more than it's height.

This mean : b = h + 3

A = b * h / 2 = ( h + 3 ) * h / 2 = 35 in ^ 2

( h * h + 3 * h ) / 2 = 35

( h ^ 2 + 3 h ) / 2 = 35 Multiply both sides by 2

h ^ 2 + 3 h = 70 Subtract 70 to both sides

h ^ 2 + 3 h - 70 = 70 - 70

h ^ 2 + 3 h - 70 = 0

The solutions are :

h = - 10

and

h = 7

Height can't be negative so :

h = 7 in

b = h + 3 = 7 + 3 = 10 in

A = 10 * 7 / 2 = 70 / 2 = 35 in ^ 2