Objectives
 Discover the congruence shortcuts (SSS, SAS, and ASA postulates).
 Use the AAS theorem to determine whether two triangles are congruent.
 Experiment with SSA and AAA and discover why they do not work as congruence shortcuts.
Key Terms
 Included Angle – An angle between two sides of a triangle
 AAS Theorem – AAS stands for “angleangleside”
 A theorem stating that if two angles and a nonincluded side of one triangle are congruent to the corresponding two angles and nonincluded side of another, then the triangles are congruent.
 This is a THEOREM because we can prove it using the “Third Angle Theorem”
 ASA Postulate – ASA stands for “anglesideangle”
 A postulate stating that if two angles and the included side of one triangle are congruent to two angles and the included side of another triangle, then the triangles are congruent.
 SAS Postulate – SAS stands for “sideangleside”
 A postulate stating that if two sides and the included angle of one triangle are congruent to two sides and the included angle of another triangle, then the triangles are congruent.
 SSS Postulate – SSS stands for “sidesideside”
 A postulate stating that if the sides of one triangle are congruent to the sides of a second triangle, then the triangles are congruent.
 Triangles with three pairs of congruent sides will always be congruent.
 You can prove the SSS Postulate by using the other congruence postulates; so, it can be called a Theorem.
 Triangle Congruence Postulate – A statement that proves triangles are congruent without requiring that the measures of all six pairs of corresponding parts be known.
 Third Angle Theorem – If two angles of one triangle are congruent to two angles of another triangle, the third angles are also congruent.
 You can combine ASA and AAS to make one general rule: If two angles and any side of one triangle are congruent to the corresponding two angles and side of another triangle, the two triangles are congruent.
Notes
Review 


Congruence 


Examples 
Answer: 
Answer: SAS 
Answer: True by ASA Note: Ignore the fact that they are NOT drawn to scale and are reflected.
