Construct a square of side `3 cm.`

Explanation

We know that, each angle of a square is right angle (i.e., `90^(@)`).
To construct a square of side `3 cm`, use the following steps.
(i) Draw a line segment `AB` of length `3cm` .
(ii) Now, generate an angle of `90^(@)` at points `A` and `B` of the segle of `90^(@)` at points `A` and `B` of the segment and plot the parallel lines `AX` and `BY` at these points.
(iii) Cut `AD` and `BC` of length `3 cm` from `AX` and `BY`, respectively.
(iv) Draw an angle of `90^(@)` at any one of the point `C` or `D` and join both points by a line segment `CD` of length `3cm`.
Thus , `ABCD` is the required square of side, `3cm`.

Alternate Method
To construct a square `ABCD` of side `3cm`, use the following steps
(i) Draw a line segment `AB` of length `3cm` .
(ii) Now, draw an angle `XAB = 90^(@)` at point `A` of line segment `AB.`
(iii) Cut a line segment `AD = 3cm` from the ray `AX` and join `BD`.
(iv)Now, from `D` point `C` is at a distance of `3cm` . So, having `D` as centre, draw an arc of radius `3cm`.
(v) From `B`, point `C` is at a distance of `3cm`. So, having `B` as center, draw an arc of radius `3cm` which intersect previous arc (obtained in step iv) at `C`.
(vi) join `DC` and `BC`.
Thus, `ABCD` is the required square of side `3cm.`