Sonia makes a wooden frame around a square picture. the frame is made of 4 congruent trapezoids. the shorter base is 9 in., the longer base is 12 in., and the height is 1.5 in. what is the area of the picture frame? tell me why the answer is that answer.

To find the answer you will find the area of one trapezoid, and then multiply it by four because all 4 trapezoids are congruent. To find the area of one trapezoid you will use the formula A=(b1 + b2)h/2. The b's stand for the bases and h is the height. So, (12+9) x 1.5 first. This equals 31.5. Then take 31.5 and divide by 2 to get 15.75 square inches for one. 15.75x4=63 square inches. I have included A picture to show you why a trapezoid uses the formula it does.