So I have to find the surface area of this!

Yeah, I know how to get the two triangls but not the other shape. All I know are the lengths of the sides and the fact that the one angle is 90 degrees.
Help, it's due this week.
(btw, the measurements are an estimation, so the triangles are off by a few decimals with pathegorean theorem)

I don't wanna give you the answer because I'm afraid it's wrong..
I suck at math, and it's my worst subject!