Surface Area of Solids

The surface area of a cube is $6\times (\text{side length}{)}^2$. For a side length of 4 cm: $6\times (4\times 4)=6\times 16=96{\text{ cm}}^2$.

The area of the top face is calculated as length \times width. For this cuboid: $6\times 2=12{\text{ m}}^2$.

The surface area of a cube is $6\times (\text{side length}{)}^2$. Divide 150 by 6 to get 25, then take the square root: $\sqrt{25}=5\text{ cm}$.

The total surface area of a cuboid is $2\times (lw+lh+wh)$. Here: $2\times (12\times 7+12\times 5+7\times 5)=2\times (84+60+35)=358{\text{ cm}}^2$.

The total surface area of a cuboid is $2\times (lw+lh+wh)$. Here: $2\times (15\times 10+15\times 8+10\times 8)=2\times (150+120+80)=700{\text{ cm}}^2$.

The total surface area is $2\times (lw+lh+wh)=2\times (12\times 6+12\times 8+6\times 8)=432{\text{ m}}^2$. Excluding the top face: $432-(12\times 6)=432-72=360{\text{ m}}^2$.