Question

I hope I can explain this. I can't draw the shape here, but it is a triangular prism that looks like a wedge of cheese. The height is 20 cm and the three sides are 13, 37, and 40 cm. There is also a line drawn from the corner of the two sides that are 13 and 37 cm, that makes a right angle with the side of the triangle that is 40 cm. It is 12 cm. (It is just inside the side that is 13 cm long.) I need to find the surface area and round to the nearest whole number.