Explanation:
as with dice (as a special quadratic form of a prism) such a prism has 6 sides :
top and bottom
left and right
front and back.
all we need to do is calculate the areas of the 6 sides and add them up for the total surface area. that's all that's needed.
it is not specified, but I assume this prism to be regular, as there is no additional information provided. that means the rectangles in each of the mentioned pairs are equal.
therefore we need to calculate the area only once and multiply it by 2.
so,
top and bottom :
2 × 6×4 = 2 × 24 = 48 m²
left and right :
2 × 4×2 = 2 × 8 = 16 m²
front and back :
2 × 6×2 = 2 × 12 = 24 m²
the total surface area of the prism is
48 + 16 + 24 = 88 m²