Opener 1-10-12 In a parallelogram one angle is 9 times the size of another. Find the measure of the angles and their supplements. Using the Information Given design a proof to show that opposite angles are congruent.

Opposite angles in a Parallelogram are Congruent.

Prove It: Using 2 column Paragraph Proof Using Flow Chart

Paragraph Proof Given: ABCD is a Parallelogram Prove: Angle A Congruent to Angle C Angle B Congruent to Angle D Opposite sides of a parallelogram are congruent, so _______ and ________. By Reflexive Property of Congruence, ________. Triangle ABD is congruent to Triangle CDB because of the _______ Congruence Postulate. Because _______ parts of congruent triangles are congruent. Angle A Congruent Angle C

Two Column Proof http://www.teachertube.com/viewVideo.php?video_id=20743&title=Proof___Opposite_Angles_of_a_Parallelogram_are_Congruent

Prove: T G Given: Parallelogram LENS and Parallelogram NGTH Prove: H N Angle L Congruent Angle T LS Parallel to GT Angle E supplementary to Angle T H N E S L

Exit Slip Pick One of the following Pg. 317 in Textbook: # 48 #49 #50