Bell Ringer We know that opposite sides of parallelograms

are both congruent and parallel. We know that opposite angles of parallelograms are congruent. We know the diagonals of a parallelogram bisect each other. We know that consecutive angles of a parallelogram are supplementary. We use what we know to prove that quadrilaterals are parallelograms.

COPY the Concept Summary on p. 340 in the Geometry book “Proving Quadrilaterals are Parallelograms”. You will need to memorize this list!

Proving a Quadrilateral is a ParallelogramTuesday, February 2, 2016

Two-Column Proofs Ex. 1:

Statements Reasons

1. 1.

2. 2.

3. 3.

Two-Column Proofs Ex. 2:

Statements Reasons

1. 1.

2. 2.

3. 3.

4. 4.

Two-Column Proofs Ex. 3:

Statements Reasons

1. 1.

2. 2.

3. 3.

4. 4.

5. 5.

Two-Column Proofs Ex. 4:

Statements Reasons

1. 1.

2. 2.

3. 3.

Two-Column Proofs Ex. 5:

Statements Reasons

1. 1.

2. 2.

3. 3.

ParallelogramProof

Cut Outs

Assignments In partner pairs, complete the 3 Classwork Cut Out Proofs.

Homework: One Cut Out Proof.

Exit TicketHow many ways can you prove a quadrilateral is a parallelogram? List them.