5.2 Proving Triangles are Congruent: SSS and SAS Textbook pg 241

SSS Side-Side-Side If three sides of one triangle are congruent to three sides of a second triangle, then the two triangles are congruent. A BC D E F AB = FE, BC = ED, CA = DF So, ABC = FED

included an included side occurs BETWEEN two angles, an included angle occurs BETWEEN two sides A B C AB is included between <A and <B <A is included between AB and AC

SAS Side-Angle-Side 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 are congruent A BC D EF If AB = DE & AC = DF & <A = <D, then ABC = DEF

How to Write a PROOF List the given information first. Use the information from the diagram. Give a reason for every statement. Use the given information, definitions, postulates and theorems as reasons. List statements in order. If a statement relies on another statement, list it later than the statement it relies on. End the proof with the statement you are trying to prove.

Examples pg

Homework: Assignment # 2 Page 245 Problems 1-37, 42-47