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

100

P(4, -2) is translated 3 units left and 2 units down, then reflected over the x-axis. Find the coordinates of P'.

P'(1,4)

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

200

P(-3, 5) is reflected over the y-axis and then rotated 90° CCW. what are the coordinates of P'?

p'(-5, 3)

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

300

Point A is in Quadrant II. Point A is first rotated 180°, reflected over the Y axis, and then translated left. What quadrant is Point A''' in?

Quadrant III

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

Which additional congruence given would allow these triangles to be congruent by ASA?

ASA  if  <F = <Q

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?

400


First, reflect over the x-axis.

Second, Translate (x+3, y+1).

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

What additional information is necessary for the triangles to be congruent by SAS?

SAS  if  EG=RP

500

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

What is Angle F = 90 degrees?

500


x = 5

y= 11

z = 7

500

Find the composition of two transformations that produces the image given the preimage below.

First, rotate 90° CCW.

Second, reflect over the x-axis.

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