Proofs for Quadrilaterals

Determine the correct reason for statement #4.

• opposite sides of a parallelogram are congruent theorem

• all sides are parallel

• sides are congruent

• sides are supplementary

What is the "reason" for step 5 of the proof?

• Angle Bisector Theorem

• Reflexive property

• CPCTC Theorem

• Proof

• ASA

• SAS

• AAS

• SSS

Fill in the Reason.

• Opposite sides of a parallelogram are congruent.

• definition of parallelogram

• Prove

• CPCTC

Fill in the missing reason for the proof.

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

• Definition of parallelogram

• Definition of parallel lines

• Opposite sides of a parallelogram are congruent.

What is reason #4?

• Same-side interior angles theorem

• alternate interior angles theorem

• consecutive angles theorem

• supplementary angles

The missing reason is the same for steps 2 and 4. What is the missing reason?

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

• If vertical angles are congruent, then the lines are parallel.

• Definition of parallelogram

• Alternate interior angles formed by parallel lines are congruent.

Given this information, which quadrilateral is proven?

• Parallelogram

• Rectangle

• Rhombus

• Square

Is the quadrilateral a parallelogram? If yes, state how you know.

• Opposite angles equal

• Opposite sides parallel

• Opposite sides equal

• Not enough info

Is the quadrilateral a parallelogram? If yes, state how you know.

• Opposite sides equal

• Diagonals bisect each other

• Opposite angles equal

• Not enough info