I’m pretty sure surface area is all the sides multiples then added I’m going to assume the length is 10, width is 4, and height is 3 You would find the base of the rectangle which is the same as the top and that would be 80 (because 10 multiples by 4 for the base and top) Then the ends which is 3x4= 12 and you have to sides so the total is 24 And lastly the sides which is 10x3= 30 and you have 2 sides so it’s really 60 In total you have 60+24+80= 164cm
