The height of a triangle is 7 ft more than its base. if the area of the triangle is 30 ft^ what is the lentgh of the base

Since the area of a triangle is in the form

area=0.5 (base) (height)

height=base+7

let base=x

area=0.5 (x) (7+x)

30=3.5x+0.5x^2

multiply the equation by 2

60=7x+x^2

subtract 60 from both sides

x^2+7x-60=0

(x-5) (x+12) = 0

thus x=5 or x=-12 since we are only considering positive answers

x=-12 is rejected

so base=5 and height=5+7=12