1. Congruent Figures Objective: 1) To recognize  figures & their corresponding parts

2. Congruent Polygons Are the same size and the same shape. Are the same size and the same shape. Fit exactly on top of each other Fit exactly on top of each other Have  corresponding parts: Have  corresponding parts: Matching sides and  s Matching sides and  s

3. You can make 3 kinds of moves so that one congruent figure can fit exactly on top of top of another

4. You can make 3 kinds of moves so that one congruent figure can fit exactly on top of top of another These are called translations and are covered in chapter 9

5. You can make 3 kinds of moves so that one congruent figure can fit exactly on top of top of another

8. ΔQXT  ΔPHD QX  PH

9. Naming Polygons Order Matters!! Order Matters!! A B C D E S TU W R ABCDE  WUTSR AB  ED   B   D   A  WU RS UU SS WW

10. Example: ΔWYS  ΔMKV m  W = 25 m  W = 25 m  Y = 55 m  Y = 55 Find m  V Find m  V W Y S M K V 25 55 100

11. Example 2: Congruence Statement Finish the following congruence statement: ΔJKL  Δ_ _ _ K J L M N ΔJKL  ΔNML

12. Proof: Th(4-1) If 2  s of one Δ are  to 2  s another Δ, then the third  s are also . If 2  s of one Δ are  to 2  s another Δ, then the third  s are also . Given:  B   E Given:  B   E  A   D  A   D Prove:  C   F Prove:  C   F A B C D F E

13. Statements 1)  B   E &  A   D 2)m  B + m  A + m  C = 180 m  E + m  D + m  F = 180 3) m  B + m  A + m  C = m  E + m  D + m  F 4)m  B + m  A + m  C = m  B + m  A + m  F 5)m  C = m  F 6)  C   F Reasons 1)Given 2)Def. of Δ 3)Trans. 4) Subs. 5)Subtr. 6)Def. of 

14. Example Proof: Proof: Given: GC  GD CN  DN CN  DN Prove: ΔGCN  ΔGDN G C N D

15. G N D C Show all of the parts are  3 sides 3 angles given reflexive given Thm 4-1