Wednesday, February 25, 2009
Geometry (Class 54)
Lesson Title
Using Congruent Triangles (2)
Overview
The opener for today will be a construction puzzle. We will then continue with working with using congruent triangles to prove other facts. As time permits we will start to investigate triangles which are the same shape, but not the same size.
Textbook Sections
Vocabulary
construction
straight edge
arc
radius
center
diameter
adjacent
opposite
included
non-included
SSS
ASA
SAS
AAS
HL
Key Attitudes
Math is about building up understanding one idea at a time.
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 key angle and side combinations which force triangles to be congruent.
I can identify and sequence the reasons which establish triangle congruence.
I can use congruent triangles to prove other facts.
I can use a straight edge and compass to construct geometric shapes.
Turn-In (#53)
Finish Opener
Txt. p.240 #20-25, 34
Handouts
No Handouts Posted
Assignment
Txt. p.255 #1-20
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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