Answer: B
Total surface area = 320 m^2
Explanation:
The figure is a combination of a cuboid and pyramid.
The Surface Area of a Pyramid When all side faces are the same:
[Base Area] + 1/2 × Perimeter × [Slant Length]
Let us use pythagorean theorem to calculate the slant length
Slant length = root(6^2 + 4^2)
Slant length = 7.2 m
Base area = 8 × 8 = 64 m^2
Perimeter = 8+8+8+8 = 32 m
Surface area of the pyramid will be
= 64 + ( 1/2 × 32 ) × 7.2
= 64 + 16 × 7.2
= 64 + 115.4
= 179.4 m^2
The surface area of the cuboid will be
LB + LH + BH = 8×8 + 8×5 + 8×5
= 64 + 40 + 40
= 144 m^2
Total surface area = 179.4 + 144
Total surface area = 323.4 m^2
= 320 m^2 to the nearest whole number.