DO NOW• Identify the corresponding parts using tick marks. Then state which

polygons are congruent.1.

2.

LET’S CHECK WHAT WE KNOW…• Using the homework key, check your answers with a partner.

• Then check your knowledge using the practice sheet. Answers will be posted shortly!!

PROVING TRIANGLES CONGRUENT

• We can prove that triangles are congruent without having all six corresponding parts congruent!

• All we need are 3!!!

WOW!OMG!!

NO WAY!

WAYS TO PROVE TRIANGLES CONGRUENT• Side-Side-Side (SSS): if all corresponding sides are congruent

• Side-Angle-Side (SAS): if two corresponding sides and the corresponding angle between those sides are congruent

• Angle-Side-Angle (ASA): if two corresponding angles and the corresponding side between those angles are congruent

• Angle-Angle-Side (AAS): if two corresponding angles and the side that is not between those angles are congruent

• Hypotenuse-Leg (HL): if the hypotenuse and a leg of one right triangle are congruent to the hypotenuse and corresponding leg of another right triangle

LET’S PRACTICE…

• First, basic proofs, then two-column proofs!