1. CONGRUENT TRIANGLES

2. Congruence We know… Two SEGMENTS are congruent if they’re the same length. Two ANGLES are congruent if they have the same measure. 2” 60 °

3. Third Angles Theorem If two angles of one triangle are congruent to two angles of a second triangle, then: The third angles are also congruent The two triangles are SIMILAR (but not necessarily CONGRUENT)

4. Triangle Congruence Congruence: Two triangles are CONGRUENT if (and only if) they have three pairs of congruent sides and three pairs of congruent angles.

5. Corresponding Parts If two triangles are congruent, then: The corresponding sides are the sides that are congruent The corresponding angles are the angles that are congruent

6. Minimum Information for Congruence There are three angles and three sides to every triangle, so there are six pieces of information. We need to know that at least THREE pieces of information match (with some restrictions).

7. Theorem #1: SSS If the side lengths of two triangles are congruent, then the triangles are congruent.

8. Theorem #2: SAS If two sides and the angle between them are congruent, then the triangles are congruent.