Algebra 1: Common Core (15th Edition)

The area of a triangle has the following equation: $Area= 1/2(base)(height)$. We are told that the area is 120 square inches and the height is 15 inches, so we plug these numbers into the equation to obtain: $120=(1/2)(15)(base) \\\\ 120=15/2(base)$ Because the variable, the length of the base, is being multiplied by a fraction, we cancel this out by multiplying by the fraction's reciprocal—2/15—to obtain that the length of the base=16 inches.