I count three rectangles and 2 triangles.
Top rectangle 15×12
Bottom rectangle 15×13
Back rectangle 15×5
The triangles are right triangles, sides 5,12,13. So the legs are base and height
Two Triangles 2×(1/2)×5×12
Adding it all up
A = 15×12 + 15×13 + 15×5 + 2×(1/2)×5×12
A = 15(12 + 13 + 5) + 5×12
A = 15(30) + 60 = 17(30)
A = 510
Answer: 510 square feet
