A triangle is cut from a rectangle. The height of the triangle is half of the unknown side length s. The area of the shaded region is 84 square inches. Write an equation you can use to find the side length s.
84 = 1/2bh ----->but h = 1/2s
84 = 1/2b(1/2s)
84 = 1/4b(s) multiply by 4 on both sides
84 x 4 = bs
336 = bs divide both sides by b
s = 336 / b