Proving Lines Parallel: Key Concepts and Techniques

What is the relationship between corresponding angles when two lines are parallel?

• They are equal to 90 degrees.

• They are complementary.

• They are congruent.

• They are supplementary.

If two angles are corresponding and the lines are parallel, what can be said about their measures?

• They are equal.

• They add up to 180 degrees.

• They are complementary.

• They are both acute angles.

What is the sum of the measures of same side interior angles when the lines are parallel?

• 90 degrees

• 360 degrees

• 180 degrees

• They are equal

Which postulate states that if two lines are cut by a transversal and corresponding angles are congruent, then the lines are parallel?

• Corresponding Angles Postulate

• Perpendicular Lines Postulate

• Alternate Interior Angles Postulate

• Same Side Interior Angles Postulate

According to the theorems, if two lines are cut by a transversal and alternate interior angles are congruent, what can be concluded?

• The lines are skew.

• The lines are intersecting.

• The lines are perpendicular.

• The lines are parallel.

What must be true for two lines to be parallel if they are cut by a transversal and same side interior angles are supplementary?

• The lines are perpendicular.

• The lines are parallel.

• The lines are skew.

• The lines are intersecting.

If two lines are parallel to a third line, what can be said about the relationship between the two lines?

• They are intersecting.

• They are perpendicular.

• They are parallel to each other.

• They are skew.

What is the value of X if 3x + 20 = x + 50 and the lines are parallel?

• 25

• 15

• 20

• 10

What is the value of Y if 2y - 5 + x + 50 = 180 and x = 15?

• 50

• 60

• 70

• 80

Which of the following is NOT a way to prove that lines are parallel?

• Show that a pair of alternate interior angles are congruent.

• Show that a pair of corresponding angles are congruent.

• Show that a pair of same side interior angles are supplementary.

• Show that a pair of vertical angles are congruent.