For example, a proposition: Isoangle is antipodal angle.

If two angles are equal, then they are antipodal angles.

Like this proposition, it is a false proposition at first glance. If you give a reason, you can draw a picture. Two angles that are not close are equal, but not diagonal. (from the definition of vertex angle)

To tell the reason, you can draw a picture or give a counterexample.

This kind of exam is usually to write questions or conclusions. If you write reasons, it is unlikely to take the exam.