5.3SAS Congruence
Quick Answer
SAS (Side-Angle-Side): if two sides and the included angle of one triangle are congruent to those of another, the triangles are congruent. The angle must be between the two sides.
Essential Question
What makes SAS different from SSA, and why must the angle be the included angle for this shortcut to work?
Learning Goals
- 1State the SAS Congruence Postulate.
- 2Identify the included angle between two given sides.
- 3Distinguish SAS from SSA (which is not a valid shortcut).
- 4Write a two-column proof using SAS.
Key Vocabulary
SAS Congruence Postulate
If two sides and the included angle of one triangle are congruent to those of another, the triangles are congruent.
Included angle
The angle formed between two given sides of a triangle.
SSA
Side-Side-Angle — NOT a valid congruence shortcut; does not guarantee congruence.
Full lesson content coming soon
Worked examples, guided practice problems, a workbook, quiz, and downloadable PDF resources will be added to this lesson in Phase 2. The learning goals and vocabulary above reflect the complete lesson scope.