Congruence Postulates Lesson 6.6 Congruence Postulates pp. 240-244

Objectives: 1. To identify and use the Side-Angle- Side and Angle-Side-Angle postulates for congruence of triangles. 2. To use the definition of congruent triangles to prove parts of triangles congruent.

Postulate 6.2 SAS Congruence Postulate. If two sides and an included angle of one triangle are congruent to the corresponding two sides and included angle of another triangle, then the two triangles are congruent.

A B C D E F ABC  DEF

Postulate 6.3 ASA Congruence Postulate. If two angles and an included side of one triangle are congruent to the corresponding two angles and included side of another triangle, then the two triangles are congruent.

J S H I Q R HIJ  QRS

EXAMPLE 1 Given: LM  LO; MLN  OLN Prove: LMN  LON M N O L

EXAMPLE 2 Given: LN bisects MLO and MNO Prove: M  O M N O L

Homework pp. 242-244

►A. Exercises Look at the markings on the triangles in each exercise and state which postulate you would use to prove that the two triangles are congruent. If neither of the postulates would apply as indicated by the markings, write neither.

►A. Exercises 1. 1. SAS 2. ASA 3. Neither

►A. Exercises 3. 1. SAS 2. ASA 3. Neither

►A. Exercises 3.

►A. Exercises 5. 1. SAS 2. ASA 3. Neither

►A. Exercises 7. 1. SAS 2. ASA 3. Neither

■ Cumulative Review 24. Perimeter Express each distance as a number or algebraic expression. 24. Perimeter 5 x 3x

■ Cumulative Review Express each distance as a number or algebraic expression. 25. AB A B C x 8

■ Cumulative Review 26. Perimeter Express each distance as a number or algebraic expression. 26. Perimeter 4

■ Cumulative Review 27. Circumference Express each distance as a number or algebraic expression. 27. Circumference 3

■ Cumulative Review 28. Circumference Express each distance as a number or algebraic expression. 28. Circumference x 2x 3x – 1

■ Cumulative Review Express each distance as a number or algebraic expression. 29. AC x+2 A B C