Well there's 2 right triangles that seem to be equivalent, so use the formula ab/2 for the right triangle. (a and b are the legs) (5*12)/2 = 60/2 = 30. There's 2 of the triangles, so multiply it by 2, which gets you 60. Now for the rectangles. The 2 large rectangles seem to be equal, so we will use w*l, which is 8 * 13 = 104. There's two of these rectangles, so multiply it by 2, which gets you 208. Sorry, I'm not sure what the little rectangle in the middle is, however, we know that it's at least 208 + 60 = 264. So now we have the last two options as our only possibilities. That small rectangle would have to have an area of only 19 if the total surface area is 283, so I think 300 is the only plausible answer choice.
