Respuesta :

Area of the triangle = (1/2)*base*height

base = x

height = altitude = x+6

Area of the triangle = (1/2)*x*(x+6) = 108

(1/2)*x*(x+6) = 108

x²+6x-216 =0

(x+18)(x-12)=0

x=-18, or x=12

We can use only positive value, so x=12.

Base =12 cm.