1. Geometry
4.1 Congruent Figures

2. Congruent Figures
Two objects are congruent ( ) if they have the same size and shape
Two figures are congruent if and only if their vertices can be matched up so that corresponding parts (angles and sides) of the figures are congruent.
When writing which figures are congruent, be sure to write the vertices in the same order.

3. A R B C S T
Triangle ABC
Triangle RST

4. A R B C S T
Triangle ABC
Triangle RST

5. D M A J B C K L
Quadrilateral ABCD
Quadrilateral JKLM

6. D M A J B C K L
Quadrilateral ABCD
Quadrilateral JKLM

7. Congruent Figures
Sometimes you have to change the position of the figures to match up vertices
Practice “spinning” and “sliding” the figures mentally

8. SPIN and SLIDE

9. Defn. of Congruent Triangles
Two triangles are congruent ( ) if and only if their vertices can be matched up so that the corresponding parts (angles and sides) of the triangles are congruent. A E D F B C

10. Defn. of Congruent Triangles
Two triangles are congruent ( ) if and only if their vertices can be matched up so that the corresponding parts (angles and sides) of the triangles are congruent.
∆ ABC ∆ DEF A 7 7 D
The order must match. B 7 7 E A D C 7 7 F AB DE BC EF B C E F CA FD

11. CPCTC
When the definition of congruent triangles is used in a proof, use the wording:
“corresponding parts of congruent triangles are congruent”
CPCTC

12. Name 3 pairs of corresponding sides.
Name 3 pairs of corresponding angles.
Is it correct to say M A B N O Y ?

13. Complete the statements given .B D A
Why is ?

14. Name the coordinates of B, I, and G.P
Name the coordinates of B, I, and G.
Name the coordinates of a point D, such that .
Name the coordinates of a point O, such that .

15. Homework
pg #1-6, 10-13, (15-21 odd)
Makeups next week are Wednesday after school
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