Help with these questions be careful for #12 in the figure the number that is in the bottom is 20ft and for the first one there si more than one answer okay

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