Géométrie

Exterior Angle Calculator | Triangle Geometry Tool

Easily calculate the exterior angle of a triangle using our online calculator. Enter two interior angles and instantly find the exterior angle. Learn about exterior angles with visualizations and examples.

Enter Interior Angles

The exterior angle of a triangle is equal to the sum of the two non-adjacent interior angles.

Result:

°

Visualization

Visual representation of the exterior angle. The exterior angle is formed by extending one side of the triangle.

Interior Angle 1Interior Angle 2Exterior Angle

Understanding Exterior Angles

In geometry, an exterior angle of a triangle is the angle between one side of a triangle and the extension of an adjacent side. For each vertex of a triangle, there are two exterior angles which are vertically opposite and hence equal.

Key Property: The exterior angle of a triangle is equal to the sum of the two opposite interior angles. This calculator uses this property to quickly determine the exterior angle.

Formula: If the two non-adjacent interior angles are \( \angle A \) and \( \angle B \), then the exterior angle \( \angle E \) is given by:

Exterior Angle (\( \angle E \)) = \( \angle A + \angle B \)

This tool is helpful for students, educators, and anyone needing to quickly calculate exterior angles in geometry problems or real-world applications.