The answer is D : 240square cm
Work out the area of the triangular face first, then multiply by 2 to get the area of both triangular faces : 6x4 then divide by 2 to get area of a triangle, the multiplied by 2 give 24 cm squared
Work out the area of the 2 slanted rectangles : (7x12)x2 which is 168
Then work out the area of the base rectangle: 12x4 =48
Finally, add them together to get the total surface area which is 240 cm squared