4.3 HW Exterior Angle Theorem

Front

What is the Exterior Angle Theorem?

Back

The Exterior Angle Theorem states that the measure of an exterior angle of a triangle 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°, what is the measure of the exterior angle adjacent to it?

Back

The exterior angle is 130° (180° - 50°).

Front

How do you find the measure of a missing angle in a triangle?

Back

To find a missing angle in a triangle, use the fact that the sum of all interior angles in a triangle is 180°. Subtract the sum of the known angles from 180°.

Front

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

Back

The sum of the interior angles of a triangle is always 180°.

Front

If angle A = 40° and angle B = 60°, what is angle C?

Back

Angle C = 80° (180° - 40° - 60°).

Front

What is an exterior angle?

Back

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

Front

If angle A is 70° and angle B is 50°, what is the measure of the exterior angle at vertex C?

Back

The exterior angle at vertex C is 120° (70° + 50°).

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

In a triangle, if one angle is 90°, what type of triangle is it?

Back

It is a right triangle.

Front

What is the measure of an exterior angle if the two opposite interior angles are 30° and 50°?

Back

The exterior angle measures 80° (30° + 50°).