Construct an equilateral triangle with alititude 4.2 cm? With figure and steps of construction

steps of constructions:

1. let us draw a straight line m.

2. draw another line l parallel to m at a distance of 4.2 cm.

3. let us take a point A on l. at point A draw the angles of 60 deg and 120 deg.

4. let it intersect the line m at points B and C respectively.

thus triangle ABC is the required triangle.