Why is it better to use a divider than a ruler, while comparing two line segments?

In the adjacent figure $\angle AOB$ and $\angle BOC$ are given. Which angle is clockwise and which angle is anti clockwise.

Which are obtuse angles?

Classify the following angles into acute, right, obtuse and straight angles.

$40°, 140°, 90°, 210°, 44°, 215°, 345°, 125°, 10°, 120°, 89°, 270°, 30°, 115°, 180°$

An angle smaller than right angle is acute angle.