Angle Relationships and Triangles

Front

What are corresponding angles?

Back

Corresponding angles are pairs of angles that are in similar positions at each intersection where a straight line crosses two others. They are equal in measure.

Front

If m∠1 = 30°, what is m∠3 if ∠1 and ∠3 are corresponding angles?

Back

m∠3 = 30°.

Front

What is the sum of the angles in a triangle?

Back

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

Front

What are alternate interior angles?

Back

Alternate interior angles are pairs of angles that lie on opposite sides of the transversal and inside the two lines. They are equal in measure.

Front

If m∠4 = 76°, what is the measure of the missing angle ∠5 if ∠4 and ∠5 are supplementary?

Back

m∠5 = 180° - 76° = 104°.

Front

What are vertical angles?

Back

Vertical angles are the angles opposite each other when two lines cross. They are equal in measure.

Front

Identify the relationship: ∠1 and ∠5 are vertical angles. What can you say about their measures?

Back

m∠1 = m∠5.

Front

If m∠2 = 60° and ∠2 and ∠3 are supplementary, what is m∠3?

Back

m∠3 = 180° - 60° = 120°.

Front

What is the measure of an angle that is complementary to a 45° angle?

Back

The measure is 90° - 45° = 45°.

Front

If two angles are complementary and one angle measures 30°, what is the measure of the other angle?

Back

The other angle measures 90° - 30° = 60°.