400 square feet
1. We're going to find the area of the trapezoid. We can divide the trapezoid into 2 parts: a rectangle and two triangles.
When we calculate the area of a right triangle, we use the formula: (a×b)/2
But we're not going to divide by two because there are two right triangles. So the area of the two right triangles would be: a×b
a = 10 ft
b = (20-12)÷2 = 8÷2 = 4ft
a×b = 10×4 = 40 ft²
Now that we found the area of the two triangles, we can find the area of the rectangle part of the trapezoid. We use the formula: a×b
a = 12 ft
b = 10 ft
a×b = 12×10 = 120 ft²
Lastly, we sum the area of the two triangles and the rectangle:
40+120 = 160 ft²
2. We calculate the area of the rectangle on the right. We use the formula: a×b
a = 12 ft
b = 20 ft
a×b = 12×20 = 240 ft²
3. We sum the area of the trapezoid and the rectangle:
160 ft² + 240 ft² = 400 ft²