When any side of a triangle is extended, the angle that is formed with this side and its adjacent side is called the exterior angle of a triangle. There are three exterior angles in a triangle.
Exterior Angles in a Triangle - MathBitsNotebook (Geo)
d1whtlypfis84e.cloudfront.net/guides/wp-content/up
Interior and Exterior Angles of Triangles (Video & Examples)
Lesson Explainer: Interior and Exterior Angles of Triangles
Triangle: Definition, Parts, Properties, Types, Formulas
Types of Triangles – Definitions, Properties, Examples – Full Potential Learning Academy
Angles in a Quadrilateral: Formula, Properties, Examples, Facts
Angles In A Quadrilateral - GCSE Maths - Steps & Examples
Definition--Theorems and Postulates--Exterior Angle Theorem
Angles In A Pentagon - GCSE Maths - Steps & Examples
Alternate Exterior Angles, Definition, Theorem & Examples - Lesson