If the side of a square is doubled, then the area of a square becomes

If the side of a square is doubled, then the area of a square becomes 4 times of the actual area.

If the side of a square $=2cm,$ then the area $=2\times 2=4c{m}^2$

If the side a square is doubled $=2\times 2cm=4cm$

Now the area of square $=4\times 4=16c{m}^2$

$\therefore$  original area $\times 4=4c{m}^2\times 4=16c{m}^2$