Warm-Up

Day 13 - Triangle Congruence Postulates SWBAT to prove triangles are congruent using SSS, SAS, ASA, AAS and HL

Mini-Assessment #3 Date: Thursday 10/31 (Periods 2, 4) or Friday 11/01 (Periods 1, 3) Covers: Day 10A – Pythagorean Theorem Day 10B – Similar Right Triangles / Geometric Mean Day 11 – Parallel Lines & Transversals (Corresponding Angles, Alternate Interior Angles, Alternate Exterior Angles, Same Side Interior Angles, etc) Day 12 – Isosceles Triangle, Exterior Angle, Triangle Sum

Polygon Exterior Angle-Sum Theorem The of the measures of the exterior angles of a polygon, one at each vertex, is 360. sum

Find the measures of the exterior angles.

Informal Geometry 12/7/2018 Congruent Triangles Congruent triangles have 3 congruent sides and 3 congruent angles. The parts of congruent triangles that “match” are called corresponding parts.

ORDER MATTERS!!!! In a congruence statement Everything matches up. Informal Geometry 12/7/2018 Congruence Statement In a congruence statement ORDER MATTERS!!!! Everything matches up.

Corresponding Parts of Congruent Triangles are Congruent CPCTC Corresponding Parts of Congruent Triangles are Congruent

Complete each congruence statement. B If ABC  DEF, then BC  ___ EF A C D F E

Complete each congruence statement. B If ABC  DEF, then A  ___ D A C D F E

Complete each congruence statement. B If ABC  DEF, then C  ___ F A C D F E

Fill in the blanks If CAT  DOG, then AC  ___ OD

BAT  MON N T  ___ _____  ONM _____  MO ATB NM  ____ BA TB Fill in the blanks BAT  MON N T  ___ _____  ONM _____  MO NM  ____ ATB BA TB

Fill in the blanks BCA   ____ ____   GFE EGF CAB

Complete the congruence statement. MKL _____   JKN

Complete the congruence statement. ABD _____   CBD

There are 5 ways to prove triangles congruent.

Side-Side-Side (SSS) Congruence Postulate All Three sides in one triangle are congruent to the three sides in the other triangle

Side-Angle-Side (SAS) Congruence Postulate Two sides and the INCLUDED angle of one triangle are congruent to two sides and the included angle of a second triangle.

Angle-Side-Angle (ASA) Congruence Postulate Two angles and the INCLUDED side (the side is in between the 2 marked angles)

Two Angles and One Side that is NOT included Angle-Angle-Side (AAS) Congruence Postulate A S A S Two Angles and One Side that is NOT included

There is one more way to prove triangles congruent, but it’s only for RIGHT TRIANGLES…Hypotenuse Leg HL

Your Only Ways To Prove Triangles Are Congruent SSS SAS ASA AAS HL NO BAD WORDS Your Only Ways To Prove Triangles Are Congruent

2 markings you can add if they aren’t marked already

Reason: reflexive property Share a side Reason: reflexive property Vertical Angles Reason: Vertical Angles are congruent

CW: Practice Worksheet #1 – 9

Homework WS #1 – 12