Interior/Exterior Angles - Triangles

Front

What is the Triangle Sum Theorem?

Back

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

Front

If one angle of a triangle is 90°, what can you say about the other two angles?

Back

The other two angles must add up to 90° because the total must equal 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 a missing angle in a triangle?

Back

Subtract the sum of the known angles from 180°.

Front

What are interior angles?

Back

Interior angles are the angles formed inside a triangle by its sides.

Front

What are exterior angles?

Back

Exterior angles are the angles formed outside a triangle when one side is extended.

Front

What is the relationship between an exterior angle and the two opposite interior angles?

Back

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

Front

If two angles in a triangle are 38° and 57°, what is the measure of the third angle?

Back

The third angle is 85°, calculated as 180° - (38° + 57°).

Front

What is the value of x if angle a = 38° and angle b = x, and angle c = 105°?

Back

x = 37°, calculated as 180° - (38° + 105°).

Front

In a triangle, if one angle is 130°, what can you conclude about the other two angles?

Back

The other two angles must be acute, and their sum must be 50°.