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? PLEASE tell me why the answer is that answer.

Respuesta :

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.
Ver imagen Mrscomputator