I don't know how to find the surface area of this, please help.

Answer:
900 m^2
Step-by-step explanation:
Find 3 different areas and double them.
The triangle becomes a rectangle because of this.
15 x 16 = 240
17 x 10 x 2 = 340
16 x 10 x 2 = 320
Add all.
240 + 340 + 320 = 900