Monday, February 23, 2009
Geometry (Class 53)
Lesson Title
Using Congruent Triangles (1)
Overview
The class starts with students practicing their algebra skills of multiplying and factoring polynomials as well as of writing the equation of line given two points or give the slope of the line and one point though which it passes. We then turn our attention to geometry and continue our work with proving triangles congruent and using congruent triangles as the basis for proving other facts.
Textbook Sections
§4.4 (Txt. p. 220) Proving Triangles Congruent
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 factor a polynomial equation.
I can write the equation of a line given the locations of two points on the line.
I can write the equation of a line given the slope of the line and the location of one point on the line.
Turn-In (#52)
Test 9 Corrections
Txt. p.239 #8-19, 33
Handouts
Chapter 4- Lesson 4: Proving Triangles Congruent
Assignment
Finish Opener
Txt. p.240 #20-25, 34
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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