1. The area of the trapezoid (At) is:
At=A1+A2
At is the area of the trapezoid.
A1 is the area of the right triangles.
A2 is the area of the rectangle.
2. You can find the area of the right triangles (A1) by applying the formula for calculate the area of a triangle and multiply it by 2, because both triangles have the same dimensions. Then:
A1=2(bxh/2)
b is the base (b=6 inches).
h is the height (h=18 inches).
A1=2(6 inchesx18 inches/2)
A1=2(108 inches²/2)
A1=108 inches²
3. Now, you must find the area of the rectangle by applying the following formula:
A2=bxh
b is the base of the rectangle (b=15 inches).
h is the height ot the rectangle (h=18 inches).
A2=(15 inches)(18 inches)
A2=270 inches²
4. Therefore, the area of the trapezoid (At) is:
At=A1+A2
At=108 inches²+270 inches²
At=378 inches²