+Warm Up1. Write a congruence statement
2. List all corresponding sides and angles using the following congruence statement
+Agenda
1. Warm Up
2. Homework Check
3. 4-2, 4-3, 4-6 Triangle Congruence Figures
4. Homework
+ Practice 4-1 Homework Check: 1. <1 = 110, <2=120 2. <4=135, <3=90
3. <5=140, <6=90, <7=40, <8 = 90
4.
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7.
1. FCB 2. NMD 3. GTK 4.
5. 6. 7. <Q
8. RS 9. <QRS 10. SQ 11. QR
12. <QSR
+Today’s Objective
Use triangle congruence postulates and theorems to prove that triangles are congruent.
+4-2, 4-3, 4-6 Triangle Congruence Figures
Last week we found out that if two triangles
have three congruent sides and three
congruent angles then the two triangles must
be ____________
Just like with similarity, we don’t need all six of these to prove triangles are congruent.
Review
+
If the three sides of one triangle are congruent to the three sides of another triangle, then the two triangles are congruent.
+
If two sides and the included (between) angle of one triangle are congruent to two sides and the included angle of another triangle, then the two triangles are congruent.
+ Non-example of SAS:
Why can’t we use SAS to show these triangles are congruent?
+
If two angles and the included side of one triangle are congruent to two angles and the included side of another triangle, then the two triangles are congruent.
+
If two angles and a non-included side of one triangle are congruent to two angles and the corresponding non-included side of another triangle, then the triangles are congruent.
+ Special Theorem for Right Triangles:
***Only true for Right Triangles***
Remember:
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/SAA – Angle, Angle, Side (Not between)
HL – Hypotenuse, Leg
+NEVER USE THESE!!!!!!
Or the Reverse (NEVER write a curse word on your paper!!!)
+
Which Theorem proves the Triangles are congruent?
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Examples
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+Class Work
Complete the work sheet for classwork!
+Homework
Finish worksheet
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