construct an equilateral triangle whose altitude is 5.4

The steps of construction are as follows:

1) Draw a line PQ.

2) Take a point D on PQ.

3) Draw a perpendicular at D on PQ.

4) Cut DA = 5.4 cm.

5) At A construct angle DAB = angle DAC = 30 degrees.

Thus, we will obtain an equilateral triangle ABC with altitude AD = 5.4 cm.