Monday, March 23, 2009
Geometry (Class 63)
Announcements
Test Friday-- proving triangles similar, using similar triangles, perfect square trinomials.
Lesson Title
Similar Triangles (5)
Overview
The opener today continues to focus on quadratic trinomials which are perfect squares-- both factoring and using the factored form to solve equations. The lesson for the day continues with similar triangles, finishing proofs started in the last class as well as extending the work to include using the Side-Angle-Side similarity postulate.
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
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!
Triangles which are the same shape always have some key attributes.
Squaring binomials creates a pattern which can be used to solve certain types of quadratic equations.
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.
I can square a binomial by inspections.
I can recognize a perfect square trinomial.
I can factor a perfect square trinomial by inspection quickly.
Turn-In (#62)
Txt. p.483 #9-20
Handouts
No Handouts Posted
Assignment
Txt. p.483 #21-29, 33-38
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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