Exterior Angles of Triangles

Front

What is the Triangle Sum Theorem?

Back

The Triangle Sum Theorem states that the sum of all angles in a triangle is 180°.

Front

What is an exterior angle of a triangle?

Back

An exterior angle of a triangle is formed by one side of the triangle and the extension of an adjacent side.

Front

How do you calculate the measure of an exterior angle?

Back

The measure of an exterior angle is equal to the sum of the measures of the two non-adjacent interior angles.

Front

If one interior angle of a triangle is 50° and another is 60°, what is the measure of the exterior angle adjacent to the 60° angle?

Back

The exterior angle is 50° + 60° = 110°.

Front

What is the relationship between an exterior angle and its adjacent interior angle?

Back

The exterior angle is equal to the sum of the two opposite interior angles.

Front

If the interior angles of a triangle are 30°, 70°, and 80°, what is the measure of the exterior angle adjacent to the 80° angle?

Back

The exterior angle is 30° + 70° = 100°.

Front

What is the measure of an exterior angle if the two opposite interior angles are 40° and 50°?

Back

The exterior angle is 40° + 50° = 90°.

Front

How many exterior angles does a triangle have?

Back

A triangle has three exterior angles, one for each vertex.

Front

What is the sum of the exterior angles of a triangle?

Back

The sum of the exterior angles of a triangle is always 360°.

Front

If one exterior angle of a triangle is 120°, what is the sum of the two opposite interior angles?

Back

The sum of the two opposite interior angles is 120°.