Construction :
Step 1: Draw a line segment AB of length 4.5 cms.
Step 2: Take 4.5 cms as radius and A as center, draw an arc.
Step 3: Take 4.5 cms as radius and B as center, draw and arc.
Step 4: Let C be the point where the two arcs intersect, join AC and BC and label the sides.
Thus, triangle ABC is the required equilateral triangle.
Justification :
By construction, AB=BC=CA ( Radius of equal arcs)
Since all sides are equal. Therefore, triangle ABC is an equilateral triangle.
Thus, the construction is justified.