1. Week 4
Warm Up
Tell whether each statement is needed to show congruence:
1) The figures must have the same size.
2) The figures must be polygons.
Add theorem 2.1 here next year.
3) The figures must have the same shape.

2. SSS - Side Side Side Congruence
Geometry
4.3 Day 1
I will prove that triangles are congruent using the SSS and SAS Postulates.
Postulate 19
SSS - Side Side Side Congruence
If three sides of one triangle are congruent to three sides of a second triangle, then the two triangles are congruent. P M N S Q R ≅ ≅ ≅
∆MNP ≅ ∆QRS because of SSS.

3. Ex 1
Prove ∆PQW ≅ ∆TSW: P W S T Q ≅ ≅ , ≅ ,
because they are given.
∆PQW ≅ ∆TSW
because of SSS.

4. SAS - Side Angle Side Congruence
Postulate 20
SAS - Side Angle Side Congruence
If two sides and the included angle of one triangle are congruent to two sides and the included angle of a second triangle, then the two triangles are congruent. P Q S W X Y ≅
∠Q ≅ ∠X ≅
∆PQS ≅ ∆WXY because of SAS.

5. Ex 2 Prove ∆ABE ≅ ∆DCE: Statements Reasons ≅ , ∠1 ≅ ∠2 ∆AEB ≅ ∆DEC≅ ,
Given
∠1 ≅ ∠2
Vertical Angle Theorem
∆AEB ≅ ∆DEC
SAS Congruence Postulate

6. because of the reflexive property of congruence.
Prove ∆PQR ≅ ∆PSR: P S R Q ≅
they are given.
1) ≅
2) ≅
because of the reflexive property of congruence.
3) ∆PQR ≅ ∆PSR
because of SSS.

7. Is ∆PQR ≅ ∆SRQ? Give 3 congruency statement to prove it?
Do: 1
Is ∆PQR ≅ ∆SRQ? Give 3 congruency statement to prove it? P Q S R
Add theorem 2.1 here next year.
Assignment:
Textbook Page 216, all.