Our big idea today: a parallelogram is a quadrilateral with opposite sides congruent, and parallelograms have four additional properties (which we are proving with a 2-column proof or by discussion verbally).
Students checked their previous night's homework. A grade was taken on HW #14 & #15 for those who had not done so yet (A day and part of 6th period). A day students get their last test back to view grade and mistakes.
Attached is a copy of the fill-in-the-blank proof for "Opposite sides of a parallelogram are congruent. Opposite angles of a parallelogram are congruent."
There are also sketches and an argument for:
Parallelogram diagonals bisect each other.
Consecutive angles in a parallelogram are supplementary.
For homework #16, (16B on B day): pp 281-3: 1-6, 11, 16-18. AND write up C-42-45 with sketches from board or handouts (the conjectures begin on p 279).