Question

How to construct angle of 84 degree using compass with step

Answer 1

You can’t really construct an 84° with just a compass and straight edge.

You can construct 90°, and any power of two fraction of 90°:

45°, 22.5°, 11.25°, 5.625° etc

You can construct a 60°, and any power of two fraction of 60°

30°, 15°, 7.5°, 3.75°, etc

Then you can combine any combination of the above angles. But no combination of the above angles will equal exactly 84°. Without getting too carried away, the nearest you could get is 90° - 5.625° = 84.375°.