CK12 - Geometry

Note:You cannotassumethat and are collinearor that and are collinear.

Statement Reason

1. 
   
   
   
   1. Given
   
   
   
   


2. 
   
   
   
   2. 
      

      ---

      
      
   
   
   
   


3. 3. Given
   4. trianglecongruencepostulate


4. 
   

   ---

   
   


5. 
   
   
   
   5. 
      

      ---

      
      
   
   
   
   


6. Bonusquestion:Why do we haveto use threelettersto name and , whilewe can

use only one letterto name or?

Answers

1. [Diff: 1]


2. AAS trianglecongruencepostulate[Diff: 1]


3. and [Diff: 2]


4. No congruencestatementis possible[Diff: 3]


5. We can’tuse eitherAAS or ASA becausethe correspondingpartsdo not matchup [Diff: 3]
   6.. This is still true by thethirdangletheorem,evenif the trianglesare not congruent.[Diff:
   3]


6. [Diff: 1]


7. ASA trianglecongruencepostulate[Diff: 1]


8. , and [Diff: 2]


9. [Diff: 3]

Statement Reason

1. 
   
   
   
   1. Given
   
   
   
   


2. 
   
   
   
   2. Given
   
   
   
   


3. 
   
   
   
   3. Given
   
   
   4. AAS TriangleCongruencePostulate
   
   
   
   


4. 
   
   
   
   5. Definitionof congruenttriangles(if two
      trianglesare then all correspondingparts
   
   
   
   

5.

are also ).

11. We can use one letterto namean anglewhenthereis no ambiguity. So at point in the diagramfor

10 thereis only one possibleangle.At point thereare four angles,so we use the “full name”of the angles
to be specific![Diff: 2]