Peter is making new cushion covers for a chair. There are three sizes of cushions on the chair. What is the surface area of the seat back cushion?
21 in
in
10 in
Net for Seat Back
21 in
21 in
13 in
seat back
15 in
10 in arm rest
15 in
15 in
seat bottom
3 in
3 in
21 in
18 in
21 in
A. 846 square inches
B. 630 square inches
C. 320 square inches
D. 990 square inches