Answer:
300 square units
Step-by-step explanation:
Notice that the surface area is the addition of all surfaces of the object. So, one needs to add the surface of three rectangles (the lateral sides) plus two right angle triangles (the base and the top which have the exact same shape and therefore area);
These areas are:
Rectangle 5 x 8 = 40
Rectangle 12 x 8 = 96
Rectangle 13 x 8 = 104
2 triangles of base 12 and height 5 = 2 ( 12 x 5 / 2) = 60
Total surface area = 40 + 96 + 104 + 60 = 300
