how can we draw an angle of 15degree and bisect it

To construct an angle of measure15°, first of all we have to construct an angle of 60°. By bisecting this angle, we will get an angle of measure 30°. On bisecting the angle 30°, we will have the angle of measure 15°. For this, we have to follow these steps.

We already know how to construct an angle of 30°. So, i am telling you the steps of constructing the angle of  15°.

i) Taking point B as centre, open the arc of compass more than half of AB and draw an arc.

ii) From point A, on maintaining the same compass opening draw an arc which will cut the previous arc as shown below.

iii) Let this point be C.

iv) Join CM. Now, ∠CMN = 15°

In the same manner you can bisect ∠CMN = 15° to obtain its further bisector which will give an angle equal to 7.5°.

Hope you get it!!