Suppose we are given angle A
We need to draw its copy
Let’s follow these steps
1.Draw a ray OP

From point A, draw an arc of any radius
intersecting the sides at B & C

Using compass opened the same length,
draw an arc with point O as the center,
cutting OP at Q

Now, back to our angle A.
Open compass to length BC

Keeping the same radius,
Put pointed end of compass on point Q, and draw an arc.
The point where it cuts previous arc is point R.

Join OR
Thus, ∠ ROQ is the copy of ∠ A