Tuesday, February 03, 2009
Geometry (Class 47)
Lesson Title
Proving Triangles Congruent (3)
Overview
The opener today gives students a chance to review factoring algebraic expressions. The lesson for the day continues our work on proving triangles congruent.
Textbook Sections
§4.3 (Txt. p.212) Proving Triangles Congruent
Vocabulary
construction
straight edge
arc
radius
center
diameter
adjacent
opposite
included
non-included
Key Attitudes
Math is about being convinced a statement is always true.
Key Ideas
A factor answers the question “How many of these are in this”?
Triangles can be constructed out of various combinations of angles and sides.
Only some combinations of angles and sides guarantee that all triangle created with this combination will be congruent-- the same size and the same shape. Other combinations only guarantee triangles which are the same shape, and some combinations guarantee nothing at all!
When multiplying two expressions, if the bases are the same the exponents need to be added.
Key Skills
I can identify the factors of a number or an algebraic expression.
I can identify key angle and side combinations which force triangles to be congruent.
I can identify and sequence the reasons which establish triangle congruence.
I can construct a triangle given given two sides and a non-included angle (SSA).
I can construct parallel lines.
I can construct the midpoint of a segment.
I can construct a triangle given the lengths of its three sides (SSS).
I can construct a triangle given its three angles (AAA).
I can construct a triangle given two adjacent sides and an included angle (SAS).
I can construct a triangle given two angles and the included side (ASA)
I can construct a triangle given two angles and the non-included side (AAS).
Turn-In (#46)
Final Exam Free Response Corrections
Txt. p.298 #21-25, 42-46
Handouts
Practice Proving Triangles Congruent
Assignment
Practice Proving Triangle Congruent #TBA
Disclaimer- The assignment as stated in class is the official assignment. Every effort is made to keep this posting accurate, but you should refer to what was stated in class as the final word.
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