Parallel and Perpendicular Proofs

Find the value of x so that l || m.

• x = 40

• x = 36.6

• x = 23.3

• x = 20

Determine which lines, if any, must be parallel.

• None of the lines are parallel.

• Corresponding Angles Theorem

• Alternate Interior Angles Theoren

• Alternate Exterior Angles Theorem

• Consecutive Interior Angles Theorem

Which Theorem?

• Corresponding Angles Theorem

• Alternate Interior Angles Theoren

• Alternate Exterior Angles Theorem

• Consecutive Interior Angles Theorem

Which quadrilateral has diagonals that are always perpendicular bisectors of each other?

• trapezoid

• parallelogram

• rectangle

• square

If AC ⊥ BD, then ∠DBC is a right angle.

• Definition of Perpendicular Lines

• Definition of Right Angle

• Angle Addition Postulate

• Segment Addition Postulate

What is the Alternate Interior Angle Theorem?

• If two parallel lines are cut by a transversal, then the resulting alternate interior angles are congruent .

• If two angles are congruent, they are on parallel lines.

• If two parallel lines are cut by a transversal, then the angles are all congruent

• If two alternate interior angles are congruent, the lines are parallel.

• Linear Pair Perpendicular Theorem

• Lines Perpendicular to a Transversal Theorem

• Corresponding Angles Theorem

• Definition of Congruent Angles

Determine which lines, if any, must be parallel.

• None of the lines are parallel.

• 40

• 20

• 180

• 360