Introduction to Triangle Congruence

1. REVIEW:
● What is a triangle?
● What are the parts of a triangle?

2. INTRODUCTION TO
TRIANGLE CONGRUENCE

3. What is the idea of
Congruence?

4. Two geometric figures with exactly
the same size and shape.

5. ΔABC is congruent to ΔXYZ
The corresponding parts of these triangles are congruent.

6. ΔABC is congruent to ΔXYZ
The corresponding parts of these triangles are congruent.
∠A ≅ ∠X

7. ΔABC is congruent to ΔXYZ
The corresponding parts of these triangles are congruent.
∠B ≅ ∠Y

8. ΔABC is congruent to ΔXYZ
The corresponding parts of these triangles are congruent.
∠C ≅ ∠Z

9. ΔABC is congruent to ΔXYZ
The corresponding parts of these triangles are congruent.
AB ≅ XY

10. ΔABC is congruent to ΔXYZ
The corresponding parts of these triangles are congruent.
BC ≅ YZ

11. ΔABC is congruent to ΔXYZ
The corresponding parts of these triangles are congruent.
AC ≅ XZ

13. ΔBAD is congruent to ΔTHE
Name all the corresponding parts.

14. ΔQRS is congruent to ΔBRX
Name all the corresponding parts.

15. ΔEFG is congruent to ΔHFG
Name all the corresponding parts.

16. TRIANGLE CONGRUENCE
Two triangles are congruent if their vertices can be paired so that corresponding
sides are congruent and corresponding angles are congruent.
Two triangles are congruent if they have the same size and shape.
Two triangles are congruent when all corresponding sides and interior angles are
congruent.

17. TRIANGLE CONGRUENCE
ΔABC ≅ ΔDEF read as “triangle ABC is congruent to triangle DEF”.
≅ - symbol for congruency
Δ - symbol for triangle

18. 1. Complete the statement: ΔARM ≅ Δ______.
2. What is the angle congruent to ∠E in ΔARM?
3. What is the angle congruent to ∠L in ΔARM?
4. What is the angle congruent to ∠R in ΔLEG?
5. What is the name of the side congruent to RM in ΔLEG?