Question

The total surface area of a cube is $600$ cm${}^2$. Find the lateral surface area of the cube.

Answer 1

Given T.S.A. of a cube as $600$ cm${}^2$, we have to find its L.S.A. But we know T.S.A. = $6l^2$, where $l$ is the length of the cube. Hence $600=l^2$ or $l^2=100$ units. Taking square-root, we get $l=10cm$. But we also know that L.S.A. $=4l^2$.
Hence,
L.S.A. $=4\times 10\times 10=400c{m}^2$.