Exterior Angles & Angle Sum: Triangle

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. It is equal to the sum of the two opposite interior angles.

Front

State 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 60 degrees and another is 70 degrees, what is the measure of the exterior angle adjacent to the 70-degree angle?

Back

The exterior angle is 60 + 70 = 130 degrees.

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 degrees.

Front

If the interior angles of a triangle are 50 degrees and 60 degrees, what is the measure of the third angle?

Back

The third angle is 180 - (50 + 60) = 70 degrees.

Front

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

Back

To find an unknown angle in a triangle, subtract the sum of the known angles from 180 degrees.

Front

What is the relationship between the exterior angle and the interior angles of a triangle?

Back

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

Front

If an exterior angle measures 145 degrees, what are the possible measures of the two opposite interior angles?

Back

The sum of the two opposite interior angles must equal 145 degrees.

Front

What is the formula for calculating the sum of angles in a polygon?

Back

The sum of the interior angles of a polygon with n sides is (n-2) * 180 degrees.

Front

If a triangle has angles measuring 30 degrees and 60 degrees, what is the measure of the exterior angle adjacent to the 60-degree angle?

Back

The exterior angle is 30 + 60 = 90 degrees.