Common Reasons for Proofs
Congruence Statements
What congruence is missing?
Triangle Congruence
Triangle Congruence Postulates
100

            Look for shared sides... The reason that goes with this step:

                               AB=AB

What is Reflexive Property?

100

Given this congruence statement, the angle congruent to angle V.

What is 

angleH

100

1) When given parallel lines, we should look for congruent ______________________ angles.

2) If M is the midpoint of FD, what can we say is congruent?


1) Alternate Interior Angles are congruent.


2) FM = MD because M is exactly in the middle.

100

The congruence conjecture that proves these are congruent triangles.

What is SSS?

100

Are the following triangles congruent?  If so, name the congruence postulates that proves it.


What is SSS?

200

        Given: AB||DE

What is the justification for this step:

         ∠BAC ≅ ∠EDC 


What is Alternate Interior Angles are congruent when lines are parallel?

200

The side congruent to side VU

What is 

bar{HI}

200

What congruent parts information would we need to know for the triangles to be congruent by ASA?

EC = DC

200

The congruence conjecture that proves these are congruent triangles.

What is SAS?

200

Are the following triangles congruent?  If so, name the congruence postulates that proves it.


Not congruent

300

Given: C is the midpoint of AE. 

The justification for this step:

bar{AC}congbar{CE}


What is Definition of midpoint?

300

A congruence statement for the two triangles represented by:

What is

triangleMNLcongtrianglePQR

300

What congruent parts would make these triangles congruent by AAS?

AC = DE

   OR

BC = FE

300

Are the following triangles congruent?  If so, name the congruence conjecture that proves it.

What is AAS?

300

Are the following triangles congruent?  If so, name the congruence postulate that proves it.


Not congruent

400

Given:

bar{AE} text( bisects )bar{BD}

The parts of the triangle that are now congruent:


What is 

bar{BC} text( and )bar{CD}

400

The side congruent to IG

What is 

bar{UW}

400

ASA  if  <B = <E

400

Are the following triangles congruent?  If so, name the congruence conjecture that proves it.

What is SAS?

400

Are the following triangles congruent?  If so, name the congruence postulate that proves it.

What is HL?

500

Given: 

bar{BD} text( bisects )angleABC

Statement: (What parts of the triangle are now congruent: )

Reason:(What reason are these congruent?)


Statement:

 angleABD text( = )angleCBD 

Reason:

Definition of Angle Bisector

500

Congruence statement for the triangles represented by:


What is

triangleADBcongtriangleCEB

500

ASA   if  <ACD = <CAB

SAS  if  CB=AD

500

The additional information needed to prove the two triangles are congruent using HL theorem

What is Angle F = 90 degrees?

500

What CPCTC stands for.


What is Corresponding Parts of Congruent Triangles are Congruent.