Download Section 4.6

Do Now
Geometry
4.6: Prove Triangles
Congruent by ASA and AAS
Postulate 21: Angle-Side-Angle (ASA)
If two angles and the included side of one
triangle are congruent to two angles and the
included side of a second triangle, then the two
triangles are congruent.
 Example:
because of ASA.

P
Q
L
R
M
N
Theorem 4.6: Angle-Angle-Side (AAS)
If two angles and a non-included side of one
triangle are congruent to two angles and a
non-included side of a second triangle, then the
two triangles are congruent.
 Example:
because of AAS.

P
Q
L
R
M
N
Triangles are congruent when you have…
SSS
AAS
SAS
ASA
HL
Triangles are not congruent when
you have…
ASS
AAA
Review from old chapters
Bisector: Cuts the segment or angle into
two congruent pieces.
 Midpoint of a segment: Cuts the segment
into two congruent pieces.
 Perpendicular lines: Two lines that
intersect at a right angle (90 degrees).
 Vertical angles: Angles “across” from each
other- they are congruent to each other.

Are the triangles congruent, if yes write a
congruence statement and explain using
SSS, SAS, ASA, AAS, HL .
1.)
A
B
D
C
C is the midpoint of AE
E
Are the triangles congruent, if yes write a
congruence statement and explain using
SSS, SAS, ASA, AAS, HL .
2.)
P
Q
R
S
Are the triangles congruent, if yes write a
congruence statement and explain using
SSS, SAS, ASA, AAS, HL .
3.)
I
K
T
E
Examples
Complete the Proof
Flow Proof
Uses arrows to show the flow of a logical
argument.
 Each reason is written below the
statement it justifies.

Write a Flow Proof
Homework

Textbook page 250-251
 #4-20
evens