Angles Relationships in Triangle

Triangle Angle Sum Theorem

The sum of the angle measures of a triangle is 180°.

The interior is the set of all points inside the figure. The exterior is the set of all points outside the figure. An interior angle is formed by two sides of a triangle. An exterior angle is formed by one side of the triangle and the extension of an adjacent side. Each exterior angle has two remote interior angles. A remote interior angle is an interior angle that is not adjacent to the exterior angle.

Find out more about angle relationships in a triangle by reading the explanation below.

Angles Relationships in Triangle

Practice: Answer the following exercises about angle relationships in a triangle.

Angles Relationships in Triangle 1

Angles Relationships in Triangle 2