Congruent Figures Section 4 1 Recall Congruent Same

Congruent Figures Section 4 -1

Recall • Congruent – Same size, Same shape

Congruent Triangles • Are the same size and shape – This means the corresponding pieces are congruent. G F N U O E

Congruent Triangles • When given two congruent triangles – The corresponding pieces are congruent ∆FUN ∆GEO F NF OG <F <G <U <E <N <O N G UF EG NU OE O U E

CPCTC • CPCTC – “Corresponding Parts of Congruent Triangles are Congruent” IF: ∆ABC ∆XYZ then: <A <X <Z <C AB XY AC XZ Etc.

Naming the Congruence • Naming two congruent Figures – The corresponding pieces must line up L quad LFHA quad ARBE quad FLAH quad RAEB quad HALF quad BEAR F E A A H R B

Examples Always Sometimes or Never 1. ) An acute triangle is ____ congruent to an obtuse triangle. Always congruent to itself. 2. ) A polygon is ____ Sometimes congruent to another right 3. ) A right triangle is ____ triangle. 4. ) If ∆ABC ∆XYZ, <A is ____ Sometimes congruent to <Y. Always 5. ) If ∆ABC ∆XYZ, <B is ____ congruent to <Y. Sometimes congruent to YZ. 6. ) If ∆ABC ∆XYZ, AB is ____

Examples Suppose ∆TIM ∆BER. Complete the following: 7. ) IM ____ ER <M <R 8. ) ____ 9. ) ∆MTI ∆____ RBE 10. ) If ∆ABC ∆XYZ, m<B = 80, and m<C = 50, name four congruent angles. <A, <C, <X, and <Z

Examples The two triangles shown are congruent. Complete. 11. ∆PXY ∆_______ TXY P X Y T 12. <P ____ because: <T Corr. Parts of ∆ (CPCTC) _________ 13. XP ____ because: XT CPCTC _________ 14. <1 <2 because: CPCTC _________ 15. YX bisects <PYT Def. Bisector because: _______