The height of a triangle is 5 m less than its base. The area of the triangle is 42 m². What is the length of the base?
Triangle area = 1/2 b * h
h = (h-5) 42 = 1/2 * b * ( b-5)
1/2 b^2 - 2.5 b - 42 = 0 b = 12 m
+28 
