Exterior Angles of Triangle

Properties	Types / Classification	Perimeter of Equilateral Triangle	Median of Triangle	Interior of a Triangle
Exterior of a Triangle	Altitude of a Triangle	Interior Angles of Triangle	Exterior Angles of Triangle	Interior Opposite Angles of Triangle
Adjacent Interior Angle of Triangle	Congruent Triangles	Area of Triangle	Area of Triangle by Heron's Formula	Construction of Triangle (compass)

Before you study this topic, you are advised to read: Exterior of a Triangle Exterior Angles of a triangle are those angles which lie in the exterior of a triangle. Following diagram further elaborates this: In the following diagram: ∠ 1, ∠ 2 & ∠ 3 all are Exterior Angles of Triangle ABC