Answer:
1. 117 sq. in.
2. 168 sq. in.
3. 99 sq. in.
Explanation:
1. base x height = area
13 x 9 = 117 sq. in.
2. 1/2 x height x (base + base)
1/2 x 14 x (15 + 9)
1/2 x 14 x 24
Multiply 1/2 by 14 to get 7
7 x 24 = 168 sq in.
3. 1/2 d x d
1/2 x 18 x 11
Multiply 1/2 by 18 to get 9
9 x 11
Multiply 9 x 11 to get 99
9 x 11 = 99 sq. in.