Exterior angle of a triangle

- Drag the vertices A, B, C to create different types of triangles. - Use the sliders to create copies of the same triangle and prove that the external angle of a triangle is always equal to the sum of the two interior opposite angles.
View Activity View Activity

 

mrsK —

 
Resource Type
Activity
Tags
angle  angles  exterior-angle  geometry  theorem  triangles 
Target Group (Age)
8 – 18
Language
English (Australia)
 
 
GeoGebra version
4.4
Views
2443
Contact author of resource
License
CC-BY-SA, GeoGebra Terms of Use
 

Books

 
© 2025 International GeoGebra Institute