1. Take papers from your folder and put them in your binder. Place your binder, HW and text on your desk. YOUR FOLDERS SHOULD BE EMPTY current EXCEPT FOR YOUR WARM UP PAPER and current day’s classwork Please get a compass, protractor and ruler Warm-up- silently please a) find y + zb) solve for x 7 5 8 Order angles from least to greatest. Honors Geometry 8 Nov 2011

2. Objective Students will explore shortcut methods for determining whether triangles are congruent. Students will do an investigation with their group and share results with the class.

3. Homework due today Pg. 218: 1-4, 11, 14-16, 22, 23 Homework due next class pg. 224: 1-21 odds hint: use color to mark corresponding parts

4. Congruence corresponding parts– have same relative position in a geometric figure Two polygons are congruent if all their corresponding sides and angles (corresponding parts) are congruent. We will look to see if there are any shortcuts to determining congruency.

5. Congruent– same shape AND size Similar– same shape but not necessarily same size adjacent means “next to” INCLUDED ANGLE included angle The angle between two given sides. INCLUDED SIDE The side between two given angles. i ncluded side add to vocabulary AB C

6. Triangle congruence shortcuts see page 221 “included” and “adjacent” SSS Congruence shortcut Side – Side- Side SAS Congruence shortcut Side – included Angle - Side All triangles have SIX parts- 3 sides and 3 angles we will explore if we can determine triangle congruency based on three congruent parts

7. CW: complete investigation of congruency shortcuts 1) Complete handout, working with your group. 2) COMPARE your triangles with those of your group mates. 3) ANSWER- does each “shortcut” GUARANTEE congruency of the two triangles 4) TEST- SSS, SAS, ASA, SAA, SSA and AAA Be ready to discuss your results in 20 minutes.

8. Term Definition Example SSS Congruence Shortcut If three sides of one triangle are congruent to three sides of another triangle, then the triangles are congruent SAS Congruence Shortcut If two sides and the included angle of one triangle are congruent to two sides and the included angle of another triangle, then the triangles are congruent SSADOES NOT guarantee congruency not a nice word if you spell it backwards = NO guaranteed congruency!!! Chapter 4 Triangles

9. debrief what did you learn today? what was easy? what was difficult? what can I do to help you?