Question

Find the lateral surface area and total surface area of a cuboid of length $80cm$, breadth $40cm$ and height $20cm$.

Answer 1

Step 1: Find the lateral surface area of the cuboid

Given that,

Length $l$ of the cuboid $=80cm$

Breadth $b$ of the cuboid $=40cm$

Height $h$ of the cuboid $=20cm$

The lateral surface area of the cuboid of length $l$, breadth $b$ and height $h$ $=2\left(l+b\right)h$

$$\begin{gathered} =2(80+40)20 \\ =40\left(120\right) \\ =4800c{m}^2 \end{gathered}$$

Step 2: Find the total surface area of the cuboid

The total surface area of the cuboid of length $l$, breadth $b$ and height $h$ $=2\left(lb+bh+hl\right)$

$$\begin{gathered} =2\left((80\times 40)+(40\times 20)+(20\times 80)\right) \\ =2(3200+800+1600) \\ =2\left(5600\right) \\ =11200c{m}^2 \end{gathered}$$

Hence, the lateral surface area of the cuboid is $4800c{m}^2$ and the total surface area of the cuboid is $11200c{m}^2$.