Practice Work: 3.4 Proofs with Perpendicular Lines

Front

What is the Linear Pair Perpendicular Theorem?

Back

If two lines intersect to form a linear pair of congruent angles, then the lines are perpendicular.

Front

What does it mean for two lines to be perpendicular?

Back

Two lines are perpendicular if they intersect to form a right angle (90°).

Front

What is the definition of a right angle?

Back

A right angle is an angle that measures exactly 90°.

Front

What is the Perpendicular Transversal Theorem?

Back

If a transversal is perpendicular to one of two parallel lines, then it is perpendicular to the other line.

Front

What is the definition of congruent angles?

Back

Congruent angles are angles that have the same measure.

Front

What is the Lines Perpendicular to a Transversal Theorem?

Back

If two lines are perpendicular to the same line, then they are parallel to each other.

Front

If ∠CAT is a right angle, what can we say about m∠CAT?

Back

m∠CAT = 90°, by the definition of a right angle.

Front

What is the Angle Addition Postulate?

Back

If point B is in the interior of ∠AOC, then m∠AOB + m∠BOC = m∠AOC.

Front

What is the Segment Addition Postulate?

Back

If point B is between points A and C, then AB + BC = AC.

Front

What is the definition of parallel lines?

Back

Parallel lines are lines in a plane that never meet and are always the same distance apart.