How many right angles are in an octagon?

Typically, ##0##

A regular octagon has ##0## right angles—all its vertices are ##135˚##.

The angle measurement can be found through the formula ##(180˚(n-2))/n##, where ##n## is the number of sides in a regular ##n##-gon.

This isn't to say octagons can't have right angles.

The following picture is of an irregular octagon with ##2## right angles.