Mr. Walker asked his students to use the associative property to find an expression that is equivalent to (13 + 15 + 20) + (20 + 47 + 18). The expressions that four students created are shown in the table below.

He trapezoid is composed of a rectangle and two triangles. what is the area of the rectangle? what is the total area of the triangles? what is the area of the trapezoid? ? a) 42 cm2; 27 cm2; 69 cm 2 b) 54 cm2; 27 cm2; 81 cm 2 c) 108 cm2; 27 cm2; 135 cm 2 d) 108 cm2; 13.5 cm2; 121.5 cm 2