Proving Triangles are Congruent ASA and AAS Chapter 4.5 Objectives: To use the ASA and AAS Theorem to prove that triangles are congruent
ASA Theorem If two angles and the included side of one triangle, are congruent to the corresponding angles and side in a second triangle, then the triangles are congruent.
ABC XYZ — Why? B C A X Z Y ASA Theorem
Use ASA in Proofs Write a two-column proof.
Step Reason L is the midpoint of WE Given Def of Midpt. Given W E Alternate Int. Thm. RLW DLE Vertical Thm. WRL EDL ASA Thm.
Write a two-column proof.
Step Reason Given CBD ADB Alternate Int. Thm. CDB ABD Alternate Int. Thm. Reflexive Property ABD CDB ASA Theorem.
AAS Theorem If two angles and a non-included side of one triangle, are congruent to the corresponding angles and side in a second triangle, then the triangles are congruent.
ABC XYZ — Why? B C A X Z Y AAS Theorem
Write a two-column proof. JNM KNL
J N M L N K IMPORTANT HINT: When you are given overlapping triangles, draw them separately.
K J L M N N Step Reason NKL NJM Given Given JNM KN L Reflexive Property JNM KNL AAS Thm.
Interactive Lab: Proofs and Congruent Triangles Homework Chapter 4-5 Pg 238 1-4, 8, 9, 15, 27 These are all two-column proofs!!! Video B 7:40- Interactive Lab: Proofs and Congruent Triangles