Geometry

Notes Section 4-5

What you’ll learn. . . .

How to use the ASA Postulate to test for triangle congruence

How to use the AAS Theorem to test for triangle congruence

Vocabulary Included side

The two shortcuts we know. . .

SSS

SAS

There are a few more. . .

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

Example #1: Find the missing congruent parts so that the triangles can be proved congruent by the ASA Postulate. Then write the triangle congruence.

a. b.

c. d.

Example #2: Write a two-column proof.

Given: PS is the angle bisector of

QPR Prove: ΔPQS ΔPRS

Might there be more????

Do you think that if two angles Do you think that if two angles and a nonincluded side of one and a nonincluded side of one triangle are congruent to the triangle are congruent to the corresponding two angles and corresponding two angles and nonincluded side of a second nonincluded side of a second triangle, the two triangles triangle, the two triangles would be congruent??would be congruent??

Today is your lucky day. . .

Yes . . .this is called AAS

Example #3: Find the missing congruent parts so that the triangles can be proved congruent. Justify your decision. Then write the triangle congruence.

Example 4:

.

Write a two-column proof.

Have you learned. . . .

How to use the ASA Postulate to test for triangle congruence

How to use the AAS Postulate to test for triangle congruence

Assignment: Non-Proof: Worksheet 4-4,4-5 Proof:p.211 (10-18 even, 21-28)