4.3 Proving Triangles Congruent – SSS, SAS HMWK: p. 216, #s 6 – 20 even, 21 – 27 odd, Game Plan: Today I will be able to use the R, S, T properties to prove triangles congruent using SSS and SAS. Warm-up: Given what you already know about the R, S, T properties and using your notes, state the R, S, T properties of congruent triangles. Use the following triangles to explain the properties. Assume all three triangles are congruent. A B C D E F G H I

4.3 Proving Triangles Congruent – SSS, SAS R, S, T Properties ~  Triangles Theorems … Reflexive: Every triangle is congruent to itself. Symmetric: If  ABC   DEF, then  DEF   ABC. Transitive: If  ABC   DEF and  DEF   GHI, then  ABC   GHI

4.3 Proving Triangles Congruent – SSS, SAS Proving Triangles Congruent With a partner, unscramble the proof using a two column format. You have all of the statements and reasons in your envelop.

4.3 Proving Triangles Congruent – SSS, SAS Proving Triangles Congruent StatementsReasons 1. MN  QP 1. Given 2. MN || PQ2. Given 3.  OMN   OQP 3. Alt. Int. Thm 4.  MNO   QPO 4. Alt. Int. Thm. 5.  MON   QOP 5. Vert. Angles 6. O is the mdpt. Of MQ & PN6. Given 7. MO  QO 7. Def. Mdpt. 8. PO  NO 8. Def. Mdpt. 9.  MNO   QPO9. Def.  

SSS and SAS Congruence notes