7
Monday
Today we will describe all the isometries of the plane!
First we’ll finish some unfinished business from yesterday.
7.1
Reflections
1. Definition:
• without coordinates
• with coordinates
2. How do we show that reflections preserve length?
3. Group of reflections?
4. Students’ understanding of reflections
7.2
Congruence
Here is something from the core:
CCSS.Math.Content.HSG-CO.B.7 Use the definition of congruence in terms of rigid motions to show that two triangles are congruent if and only if corresponding pairs of sides and
corresponding pairs of angles are congruent.
CCSS.Math.Content.HSG-CO.B.8 Explain how the criteria for triangle congruence (ASA,
SAS, and SSS) follow from the definition of congruence in terms of rigid motions.
What does that mean?
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