s proving triangles congruent ss. s as a sa a as this one is a theorem!!
TRANSCRIPT
SS
Proving Triangles CongruentProving Triangles Congruent
SSSS
SS
Proving Triangles CongruentProving Triangles Congruent
AASS
AA
Proving Triangles CongruentProving Triangles Congruent
SSAA
AA
Proving Triangles CongruentProving Triangles Congruent
AASS This one is a THEOREM!!
Proving Triangles CongruentProving Triangles Congruent
HHLL This one is a THEOREM!!
CAUTION!!CAUTION!!
BE CAREFUL!!!NOT ALL combinations S & A will give congruent triangles.
AAAAAA•AAA is NOT a method to
prove two triangles congruent. It will show two triangles that have the same SHAPE, but NOT necessarily the same SIZE!!
SSA (OR ASS)SSA (OR ASS)• This is humorously
referred to as the Donkey Theorem. It is NOT a valid way to show two triangles are congruent!!
1
LKN LMN by SAS Postulate
2
Not Congruent
3
FGH JKL by SAS Postulate
4
LKN LMN by SAS Postulate
5
Not Congruent
6
XYZ TUV by SSS Postulate
7T
E G
I
R
ERT IRG by ASA Postulate
Vertical Angles Theorem
Alternate Interior Angles Theorem