Congruent Triangles

1. Congruent Triangles An Introduction to Corresponding Parts

2. Two figures are congruent if they are the same size and same shape.

3. Congruent figures can be rotations of one another.

4. Congruent figures can be reflections of one another.

5. ∆ABC is congruent to ∆XYZ C Z A B X Y

6. ∆ABC is congruent to ∆XYZ C Z A B X Y Corresponding parts of these triangles are congruent.

7. ∆ABC is congruent to ∆XYZ C Z A B X Y Corresponding parts of these triangles are congruent. Corresponding parts are angles and sides that “match.”

8. ∆ABC is congruent to ∆XYZ C Z A B X Y Corresponding parts of these triangles are congruent. A X

9. ∆ABC is congruent to ∆XYZ C Z A B X Y Corresponding parts of these triangles are congruent. B Y

10. ∆ABC is congruent to ∆XYZ C Z A B X Y Corresponding parts of these triangles are congruent. C Z

11. ∆ABC is congruent to ∆XYZ C Z A B X Y Corresponding parts of these triangles are congruent. AB XY

12. ∆ABC is congruent to ∆XYZ C Z A B X Y Corresponding parts of these triangles are congruent. BC YZ

13. ∆ABC is congruent to ∆XYZ C Z A B X Y Corresponding parts of these triangles are congruent. AC XZ

14. ∆DEF is congruent to ∆QRS F Q S D E R

15. ∆DEF is congruent to ∆QRS F Q S D E R Corresponding parts of these triangles are congruent.

16. ∆DEF is congruent to ∆QRS F Q S D E R Corresponding parts of these triangles are congruent. D Q

17. ∆DEF is congruent to ∆QRS F Q S D E R Corresponding parts of these triangles are congruent. E R

18. ∆DEF is congruent to ∆QRS F Q S D E R Corresponding parts of these triangles are congruent. F S

19. ∆DEF is congruent to ∆QRS F Q S D E R Corresponding parts of these triangles are congruent. DE QR

20. ∆DEF is congruent to ∆QRS F Q S D E R Corresponding parts of these triangles are congruent. DF QS

21. ∆DEF is congruent to ∆QRS F Q S D E R Corresponding parts of these triangles are congruent. FE SR

22. Practice Time!

23. 1) Are these shapes congruent? Explain.

24. 1) Are these shapes congruent? Explain. These shapes are congruent because they are both parallelograms of equal size.

25. 2) Are these shapes congruent? Explain.

26. 2) Are these shapes congruent? Explain. These shapes are not congruent because they are different sizes.

27. 3) Are these shapes congruent? Explain.

28. 3) Are these shapes congruent? Explain. These shapes are congruent because they are the same size.

29. 4) ∆BAD is congruent to ∆THE Name all corresponding parts. D E A B T H

30. 4) ∆BAD is congruent to ∆THE Name all corresponding parts. D E A B T H ANGLES SIDES B T BA TH A H AD HE D E DB ET

31. 5) ∆FGH is congruent to ∆JKL Name all corresponding parts. F J G H K L

32. 5) ∆FGH is congruent to ∆JKL Name all corresponding parts. F J G H K L ANGLES SIDES F J FG JK H L GH KL G K HF LJ

33. 6) ∆QRS is congruent to ∆BRX Name all corresponding parts. S R B Q X

34. 6) ∆QRS is congruent to ∆BRX Name all corresponding parts. S R B Q X ANGLES SIDES Q B QR BR S X QS BX R R SR XR

35. 7) ∆EFG is congruent to ∆FGH Name all corresponding parts. E H G F

36. 7) ∆EFG is congruent to ∆FGH Name all corresponding parts. E H G F ANGLES SIDES E H EF HF F F EG HG G G GF GF

37. IH RS 3a = 6 3a = 6 3 3 In the figure, quadrilateral JIHK quadrilateral QRST. Find a. Divide both sides by 3. 3a I H a = 2 6 4b° S R 120° J 30° Q K c + 10° T

38. H S 4b = 120 4b = 120 4 4 In the figure, quadrilateral JIHK quadrilateral QRST. Find b. Divide both sides by 4. 3a I H 6 4b° S R b = 30° 120° J 30° Q K c + 10° T

39. K T c + 10 = 30 c + 10 = 30 –10 –10 In the figure, quadrilateral JIHK quadrilateral QRST. Find c. Subtract 10 from both sides. 3a I H 6 c = 20° 4b° S R 120° J 30° Q K c + 10° T

40. Congruent Triangles THE END