Triangle Angle Sum and Triangle Exterior Angle

Front

What is the Triangle Sum Theorem?

Back

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

Front

What are the remote interior angles of an exterior angle in a triangle?

Back

The remote interior angles are the two angles that are not adjacent to the exterior angle.

Front

If one angle of a triangle is 60° and another is 90°, what is the third angle?

Back

The third angle is 30°, since 60° + 90° + 30° = 180°.

Front

What is the measure of each angle in an equilateral triangle?

Back

Each angle in an equilateral triangle measures 60°.

Front

How do you find the measure of an exterior angle of a triangle?

Back

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

Front

If angle A = 40° and angle B = 70°, what is angle C in triangle ABC?

Back

Angle C = 70°, since 40° + 70° + C = 180°.

Front

What is the relationship between the angles in a right triangle?

Back

In a right triangle, one angle is 90°, and the sum of the other two angles is 90°.

Front

What is the formula for the sum of angles in a triangle?

Back

The formula is A + B + C = 180°, where A, B, and C are the angles of the triangle.

Front

If the exterior angle is 120°, what are the remote interior angles?

Back

The remote interior angles must sum to 120°.

Front

What is the definition of an exterior angle in a triangle?

Back

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