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

Length (l) = 80 cm
Breadth (b) = 40 cm
Height (h) = 20 cm

Now, use the formula;
$Total surface area of cuboid=2\left(lb+bh+hl\right)$

Substitute the given values in the above formula;
$$\begin{gathered} TSA=2\left[\left(80\right)\left(40\right)+\left(40\right)\left(20\right)+\left(20\right)\left(80\right)\right] \\ TSA=2\left[3200+800+1600\right] \\ TSA=2\left(5600\right) \\ TSA=11200 \end{gathered}$$

Therefore, the total surface area of the cuboid is 11200 cm²

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Now, we know that the lateral surface area of the cuboid is given by;
$$\begin{gathered} LSA=2h\left(l+b\right) \\ LSA=2\left(20\right)\left(80+40\right) \\ LSA=40\left(120\right) \\ LSA=4800 \end{gathered}$$

Therefore, the lateral surface area of the cuboid is 4800 cm²