How to construct 150 degrees by ruler and compass?

The steps for constructing 150 degree angle are as follows :

1.Draw a ray OA.

2.With O as centre and any suitable radius, draw an arc, cutting OA at B.

3.With B as centre and the same radius, cut the previously drawn arc at C, then with C as centre and the same radius, cut the arc at D,and then with D as centre and the same radius, draw another arc to cut the previous arc at E.

4.With D as centre and more than half DE, draw an arc.

5.With E as centre and the same radius, draw another arc to cut the previous arc at F.

6.Join OF.

The angle of 150 degrees is made.