h=8 in
Area of each rectangle = 12 and 3/8 squared inches.
a)The area of the glass panel is the area of the trapezoid minus the area of the rectangles. The area of a trapezoid is calculated as the following:

This is the height times 1/2 times the sum of the top edge plus the bottom edge
b)The area of the rectangles is the sum of both of them:

The area of the trapezoid is:

c) Let's say G is the area of the glass panel we must find, this equals to the area of the trapezoid minus the area of the rectangles:

d) G is then:
