Proving lines are parallel

Front

What is the Substitution Property in geometry?

Back

The Substitution Property states that if two quantities are equal, one can be substituted for the other in any expression.

Front

What is the Reflexive Property of Congruence?

Back

The Reflexive Property of Congruence states that any geometric figure is congruent to itself.

Front

What is the Transitive Property of Equality?

Back

The Transitive Property of Equality states that if a = b and b = c, then a = c.

Front

What is the Transitive Property of Congruence?

Back

The Transitive Property of Congruence states that if two figures are congruent to a third figure, then they are congruent to each other.

Front

What are Vertical Angles?

Back

Vertical Angles are the angles opposite each other when two lines intersect. They are always congruent.

Front

What are Alternate Interior Angles?

Back

Alternate Interior Angles are pairs of angles that lie on opposite sides of a transversal and inside the two lines. If the lines are parallel, these angles are congruent.

Front

What are Corresponding Angles?

Back

Corresponding Angles are pairs of angles that are in the same position on two different lines cut by a transversal. If the lines are parallel, these angles are congruent.

Front

If angle 1 = 135 degrees, what is the measure of angle 5 if lines m and n are parallel?

Back

Angle 5 = 135 degrees (because they are corresponding angles).

Front

If angle 2 = 45 degrees, what can be inferred about lines m and n?

Back

If angle 2 = 45 degrees and angle 1 = 135 degrees, lines m and n are parallel (because they are alternate interior angles).

Front

What is the relationship between angle pairs when two parallel lines are cut by a transversal?

Back

When two parallel lines are cut by a transversal, corresponding angles are equal, alternate interior angles are equal, and same-side interior angles are supplementary.