Download If two angles and the included side of one - Shope-Math

Honors Geometry 9 Nov 2011
Take papers from your folder and put them in your binder.
Place your binder, HW and text on your desk.
YOUR FOLDERS SHOULD BE EMPTY
EXCEPT FOR YOUR WARM UP PAPER and current day’s
classwork
Please get a compass, protractor and ruler
Warm-up- silently please 
QUICK QUIZ---- when your are finished, turn
your quiz upside down and place on your
group folder then….
Continue working on your Triangle
Congruency Shortcuts Handout
Objective
Students will explore shortcut methods for
determining whether triangles are congruent.
Students will do an investigation with their
group and share results with the class.
Homework due today
pg. 224: 1-21 odds
hint: use color to mark corresponding parts
Homework due Nov. 15
Pg. 229: 2 – 20 evens
add to vocabulary
Congruent– same shape AND size
Similar– same shape but not necessarily same size
adjacent means “next to”
INCLUDED ANGLE
included angle
C
The angle between
two given sides.
INCLUDED SIDE
A
B
The side between
two given angles.
included side
Triangle Congruencies
Group Discussion
SSA-- how many triangles can you make?
Constructions– SAA and AAA
how do you construct these with a compass?
http://ceemrr.com/Geometry2/Constructing_Triangles/Constructing_Triangles_print.html
Patty paper is EASIER for some constructions.
SUMMARY- WHICH SHORTCUTS– knowing
three sides are congruent– GUARANTEE that all
six parts (both triangles) are congruent?
Chapter 4 Triangles
Term
Definition
SSS
Congruence
Shortcut
SAS
Congruence
Shortcut
SSA
If three sides of one triangle
are congruent to three sides of
another triangle, then the
triangles are congruent
If two sides and the included
angle of one triangle are
congruent to two sides and the
included angle of another
triangle, then the triangles are
congruent
DOES NOT guarantee
congruency
Example
not a nice word if you
spell it backwards =
NO guaranteed
congruency!!!
90o
Chapter 4 Triangles-Term
Definition
ASA
Congruence
Shortcut
SAA
Congruence
Shortcut
AAA
Example
If two angles and the included
side of one triangle are
congruent to two angles and
the included side of another
triangle, then the triangles are
congruent.
If two angles and a nonincluded side of one triangle
are congruent to the
corresponding two angles and
non-included side of another
triangle, then the triangles are
congruent
DOES NOT guarantee
congruency
90o