Big ideas for block 9: What does a good sketch look like? How can a sketch help me detect a bad definition? Attention to detail is needed in order to successfully apply algebra to geometric sketches.
We added "skew lines" to our Geometric Truth (lines that never meet that are not co-planar). Get from a neighbor. This led us to a bad definition of parallel lines: lines that never meet are parallel. No... you must include the phrase "on the same plane". Make sure you can use all the new notations in the sketches and labels on p 48 for parallel and perpendicular and naming lines with one lower case letter.
We also did several algebra problems based on the definition and sketches of angle bisector and midpoint (attached below).
A grade was taken over HW #5 (3 pts) and HW #4 quizzes were returned. We shared our partner-written definitions for the angles on pp 49-50 and came to consensus on "linear pairs" and "vertical angles". Those are attached below to add to GT.
How is drawing (using ruler and protractor) different from sketching (free hand and label well)? We practiced several sketches from names and labels (attached below).
HW #6 and new terms for geometric truth are attached below.
Quiz of 36-40 pts on Friday, Sept 8 or Monday, Sept 11. Topics and review will be handed out on Tues-Wed.