Prove Parallelograms Are Equal

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

Fill in the Reason

• Opposite sides of a parallelogram are congruent.

• definition of parallelogram

• Prove

• CPCTC

What is reason #3? Make sure you write-in the reasons on your proofs.

• Definition of a parallelogram

• Definition of a quadrilateral

• Opposite sides are congruent property

• Opposite sides are supplementary

Choose the correct missing reasons for the proof.

• 4) CPCTC; 6)All quads are parallelograms

• 4) Alternate Interior Angles are congruent; 6) Definition of paralelogram

• 4)CPCTC; 6)Definition of parallelogram

• 4) Alternate Interior Angles are congruent; 6) All quads are parallelograms

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.

Fill in the Reason

• Opposite sides of a parallelogram are congruent.

• definition of parallelogram

• Prove

• CPCTC

Which theorem can be used to prove the quadrilateral is a parallelogram?

• Parallelogram Opposite Sides Converse Theorem

• Parallelogram Opposite Angles Converse Theorem

• Opposite Sides Parallel and Congruent Theorem

• Parallelogram Diagonals Converse Theorem

What is reason #4?

• Same-side interior angles theorem

• alternate interior angles theorem

• consecutive angles theorem

• supplementary angles

Fill in the Reason.

• Opposite sides of a parallelogram are congruent.

• definition of parallelogram

• Prove

• CPCTC

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.