Learn about angles in geometry with Khan Academy's free online resources.

Khan Academy

Learn about angles, including measuring angles with a protractor and identifying different types of angles.

Review types of angles, including acute, right, and obtuse angles.

Learn about complementary and supplementary angles, as well as the definitions of adjacent and straight angles.

Notre mission : apporter un enseignement gratuit et de qualité à tout le monde, partout. Plus de 6 000 vidéos et des dizaines de milliers d'exercices interactifs sont disponibles du niveau …

If you're seeing this message, it means we're having trouble loading external resources on our website. If you're behind a web filter, please make sure that the domains *.kastatic.org and …

Proof of the Angle Bisector Theorem.