1. Congruence and Triangles
Section 4-2
Congruence and Triangles

2. Congruent geometric figures
Have exactly the same size and same shape.

3. Corresponding angles are congruent!
When two figures are congruent…
Corresponding angles are congruent!
Corresponding sides are congruent!

4. A B C P R Q

5. Third angles theorem
If two angles of one triangle are congruent to two angles of another triangle, then the third angles are also congruent.

6. Reflexive property of congruent triangles
Every triangle is congruent to itself

7. Symmetric property of congruent triangles
If ,
then

8. TRANSITIVE property of congruent triangles
If and
, then