Do Now
• In your group, choose someone to fill each role
• Spokesperson
• Materials gatherer
• Writer
• Scorekeeper
• Reminders:
• Tutoring today
• Turn in benchmark review Friday
• Turn in Unit 2 Test corrections Friday
• Ice Cream Party Competition
• Auction on Friday
CONGRUENCY
SHORTCUTS
CPCTC
CLASSIFYING
TRIANGLES
THEOREMS
BASICS OF
PROOFS
Team 1
Team 2
Team 3
Team 4
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© 2006 by Mr. Mayers
If ΔABC≅ΔDEF, then which
angle is congruent to C?
F
Back
Are the triangles congruent? Which shortcut
tells you?
Yes, SAS
Back
Classify this triangle by its sides
Scalene
Back
What is the Triangle Sum
Theorem? Use it to find the
missing angle measure.
The sum of the angles in any
triangle is 180o,
m<C=110o
Back
What is the reflexive property?
A geometric object is congruent to
itself. (AB≅AB or <C≅<C)
Back
Which triangle congruency is
represented here?
SSS
Back
What does CPCTC stand for?
Corresponding Parts of Congruent
Triangles are Congruent
Back
Given that C is the midpoint of BE and that <A≅<D, are
the triangles congruent? Which shortcut tells you?
Yes, AAS
Back
Classify this triangle by its
angles
Obtuse
Back
Do the lengths 9, 6, and 2 form a
triangle?
No, 6+2 is not greater than 9.
Back
What are vertical angles?
Vertical Angles are opposite angles from
where 2 lines cross.
Back
Which triangle congruency shortcut is
represented here?
AAS
Back
If ΔBCD≅ΔFGH, then which side is
congruent to GH?
CD
Back
Are the triangles congruent?
Which shortcut tells you?
Yes, AAS
Back
Classify this triangle by
angles
29o, 61o, 90o
Right
Back
State the Base Angle Theorem and use it to
find the measure of <Z.
If two sides of a triangle are congruent,
then the angles opposite those sides are also
congruent. 54o.
Back
Are these two triangles
congruent? Why/ why not?
Back
Name the two triangles in this
diagram that share a reflexive
property at angle F.
Back
Name a non-marked piece of
information that is congruent.
BW≅MN, OW≅AN, or <W≅<N
Back
Are the triangles congruent? Which shortcut tells you?
No, AAA
Back
C is congruent to B and D is
congruent to E. What kind of
triangles are these?
Isosceles (and acute)
Back
What can serve as a counterexample to the conjecture
below:
“If Miguel wants to prove two triangles are congruent, he
must use ASA.”
AAS, SSS, SAS, HL
Back
Name the steps to writing a
good two column proof
Back
Fill in the following chart to complete the two-column proof.
Reflexive vertical angle
AAS
CPCTC
Back
In order to prove that CB≅ZX, what do we
have to prove first?
ΔCBA≅ΔZXY
Back
Are the triangles congruent?
Which shortcut tells you?
No, SSA
Back
What is the measure of any interior angle
of an equilateral triangle? What do we call
this type of triangle?
o
60 ,
Equiangular
Back
According to the triangle inequality theorem, if
6, 8, and x form a triangle, what are all the
possible values for x?
2<x<14
Back
Write a proof.
Back
Construct a Two Column Proof
Back