Warm Up 12/5/12 State the 6 congruent parts of the triangles below. 10 minutes End
Homework Check
If 2 Triangles have 3 Congruent Sides and 3 Congruent Angles, then the 2 Triangles are _________ Do we need all six of these to guarantee two triangles are congruent?
Today’s Objective Students will be able to use triangle congruence postulates and theorems to prove that triangles are congruent.
If the 3 sides of one triangle are congruent to the 3 sides of another triangle, then the two triangles are congruent.
If 2 sides and the included angle of one triangle are congruent to 2 sides and the included angle of another triangle, then the 2 triangles are congruent.
If 2 angles and the included side of one triangle are congruent to 2 angles and the included side of another triangle, then the two triangles are congruent.
If 2 angles and a nonincluded side of one triangle are congruent to 2 angles and the corresponding nonincluded side of another triangle, then the triangles are congruent.
Special Theorem for Right Triangles: ***Only true for Right Triangles*** Hypotenuse: Longest side, always opposite the right angle. Legs: Other 2 shorter sides (form the right angle)
Hypotenuse – Leg (HL) Theorem If the hypotenuse and a leg of one right triangle are congruent to the hypotenuse and leg of another right triangle, then the triangles are congruent.
We now have the following: SSS – side, side, side SAS – Side, Angle (between), Side ASA – Angle, Side (between), Angle AAS – Angle, Angle, Side (Not between) HL – Hypotenuse, Leg
NEVER USE THESE!!!!!! Or the Reverse (NEVER write a curse word on your paper!!!)
Proving ‘s are Which Theorem proves the Triangles are 1.
2.
3.
4.
5.
Classwork/Homework Kuta Software page 37 and 38