Interactive Powerpoint_How to Master effective communication
4.4 CPCTC
1. CPCTC
The student is able to (I can):
• Show that corresponding parts of congruent triangles are
congruent.
2. CPCTC – an abbreviation for “Corresponding Parts of
Congruent Triangles are Congruent.”
Once we know two triangles are congruent, we then know
that all of their corresponding sides and angles are
congruent.
To use CPCTC, first prove the triangles congruent using SSS,
SAS, ASA, AAS, or HL, and then use CPCTC to state that the
other parts of the triangle are also congruent.
3. Example Given: LBG OGB
Prove: L O
1. 1. Given
2. LBG OGB 2. Given
3. 3. Reflex. prop.
4. ΔLBG ΔOGB 4. SAS
5. L O 5. CPCTC
L
B
O
G
,
BL GO
BL GO
BG GB
4. Example Given:
Prove: O R
To prove the angles congruent, we can
break this shape into two triangles, prove
the triangles congruent, and then use
CPCTC to prove the angles congruent.
R
U
O
F
,
FO FR UO UR
5. Example: Given:
Prove: O R
R
U
O
F
Statements Reasons
1. 1. Given
2. 2. Given
3. 3. Refl. prop.
4. ΔFOU ΔFRU 4. SSS
5. O R 5. CPCTC
FO FR
UO UR
UF UF
,
FO FR UO UR
