Question

What is the length of the side of the square if area of the square is 9 $c{m}^2$?

• A. $1cm$
• B. $2cm$
• C. $3cm$
• D. $4cm$

Answer 1

The correct option is C $3cm$

Given,
Area of the square is 9 $c{m}^2$.

Now, let the length of the side of the square be $xcm$.

We know that square has all the sides equal.

Area of square
=length of the side $\times$ length of the side
$\Rightarrow x\times x$ = 9 $c{m}^2$

Using trial and error method\),

Case 1:

Putting length of a side of square $x=1cm$,
LHS = $1\times 1$ = 1 $c{m}^2$
Hence, LHS is not equal to RHS.

Case 2:

Putting length of side of square $x=2cm$,
LHS = $2\times 2$ = 4 $c{m}^2$
Hence, LHS is not equal to RHS.

Case 3:

Putting length of side of square $x=3cm$,
LHS = $3\times 3$ = 9 $c{m}^2$
Hence, LHS is equal to RHS.

$\therefore$ Length of side of square is $3cm$.