Respuesta :

You can consider that each little square has the dimenions of 1cm x 1cm.

The biger square has a side with four little squares, then, you can conclude that the sides of the biger square is 4cm x 4cm

side length side length

4 4

You can observe that there are 16 litle squares inside the biger one. Then, the are of the biger square is 16 cm²

Finally, you have :

√16 = 4