Sum of the angles in a triangle

Animation outlining the proof that the sum of the angles in a triangle is 180°. A line is drawn through the top vertex of the triangle which is parallel to the base and then the alternate angles are shown.

 

GreenMaths

 
Type de ressources
Activité
Balises
angle 
Tranche d'âges
11 – 14
Langue
English (United Kingdom)
 
 
 
© 2026 International GeoGebra Institute