For #11, the answers are choices 1 and 4. The first one is because it is a parallelogram so A = bh (12 x 3). The fourth choice is correct because it is a triangle with a base of 6 and a height of 12 and A = 1/2bh so 1/2 x 6 x 12 = 36.
For #12, you will find the areas of 2 rectangles.
1. A = 9 x 8
A = 20 x 9
72 + 180 = 252 square feet
For #13, you will use the formula for finding the area of a trapezoid and double it,
A = 1/2h(b1 + b2)
1/2 x 24 (40 + 60)
A = 120 square inches
120 x 2 = 240 square inches
For # 14, you will use the formula for finding the area of a trapezoid again.
A = 1/2 x 5 (9 + 11)
A = 50 square meters
50 x 2 = 100 square meters
For #15, the corner cabinet is the triangle in the corner.
Use the formula for finding the area of a triangle to find the space.
A = 1/2bh
1/2 x 3 x 3
A = 4.5 square feet