A triangle has height 15 inches and area 120 inches. what is the length of its base?

Area of triangle = 1/2 * base * height

what we know:

area of triangle = 120

height = 15

now we just substitute it in:

120 = 1/2 * base * 15

dividing by something is the same as multiplying by its reciprocal, so:

120 * 2 = base * 15

240 / 15 = base

16 = base

so, your base is 16 inches.