Using Congruent Triangles Sec 4.5

1
Using Congruent TrianglesSec 4.5

• GOAL
• To use congruent triangles to write proofs

2
Corresponding Parts of Congruent Triangles are
Congruent

• To prove triangles congruent, use either
• SSS
• SAS
• ASA
• AAS
• Once you prove two triangles are congruent, then
  you can prove that all other corresponding parts
  are congruent. The reason is that Corresponding
  Parts of Congruent Triangles are Congruent

3
Example
Given Diagram Prove The two
triangles are congruent by ASA. Now, you can say
that sides BC and AD are congruent because
corresponding parts of congruent triangles are
congruent.
B
C
B
C
A
A
D
D
4
Two Column Proof

• Given
• Prove

X
P
4
2
W
Z
3
1
Y