Construct an equilateral triangle, given its side and justify the construction.

Steps of construction
(i) Draw a line segment AB of given measurement.
(ii) Taking A and B as centre, draw arcs with same radius (equal to AB), which intersect at C.
(iii) Join A to C and B to C.
(iv) ΔABC is the required equilateral triangle.
Justification
In ΔABC,
AB = BC [∵ By construction]
AC = BC [∵ By construction]
Hence, AB = BC = AC
⇒ Triangle ABC is an equilateral triangle.