Suppose the area of a square is 84 sq.cm, find the side length.

The correct answer is:

We are given the area of a square is 84 sq. cm. We have to find the side length.
We have,
Area of a square = 84 cm².
=> (side)² = 84
=> side = √84
=> side = 2√21 cm.
Hence, the correct option is C.

Area of a rectangle is length × breadth. Since, for a square both length and breadth are equal so its area is (side)².