Triangle Angle-sum and Exterior Angle Theorem Review

Front

What is the Triangle Angle-sum Theorem?

Back

The Triangle Angle-sum Theorem states that the sum of the interior angles of a triangle is always 180 degrees.

Front

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

Back

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 angle of a triangle measures 45 degrees and another measures 55 degrees, what is the measure of the third angle?

Back

The third angle measures 80 degrees, calculated as 180 - (45 + 55).

Front

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

Back

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

Front

If the angles of a triangle are in the ratio 2:3:4, how do you find the measures of the angles?

Back

Let the angles be 2x, 3x, and 4x. The equation is 2x + 3x + 4x = 180, leading to x = 20. The angles are 40, 60, and 80 degrees.

Front

What is the definition of an acute angle?

Back

An acute angle is an angle that measures less than 90 degrees.

Front

What is the definition of an obtuse angle?

Back

An obtuse angle is an angle that measures more than 90 degrees but less than 180 degrees.

Front

How do you find the value of x in a triangle when given two angles?

Back

Use the Triangle Angle-sum Theorem: x = 180 - (sum of the given angles).

Front

What is the formula for the sum of the interior angles of a polygon?

Back

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

Front

If one exterior angle of a triangle is 120 degrees, what are the measures of the two non-adjacent interior angles?

Back

The sum of the two non-adjacent interior angles is 120 degrees.