1. 4-4 Proving Triangles Congruent (SSS, SAS) Ms. Andrejko

2. Real World

3. Vocabulary Included Angle- the angle formed by 2 adjacent sides of a polygon

4. Postulates/Theorems P 4.1: If 3 sides of one triangle are congruent to three sides of a second triangle, then the triangles are congruent. P 4.2: If 2 sides of the included angle of one triangle are congruent to 2 sides and the included angle of a second triangle, then the triangles are congruent

5. Examples Determine which postulate can be used to prove that the triangles are congruent. If it is not possible to prove congruence, write not possible.

6. Practice Determine which postulate can be used to prove that the triangles are congruent. If it is not possible to prove congruence, write not possible.

7. Examples Determine whether ΔDEF ≅ ΔPQR given the coordinates of the vertices. D(-6, 1), E(1, 2), F(-1, -4), P(0, 5), Q(7, 6), R(5, 0)

8. Practice Determine whether ΔDEF ≅ ΔPQR given the coordinates of the vertices. D(-7, -3), E(-4, -1), F(-2, -5), P(2, -2), Q(5, -4), R(0, -5)

9. Practice Determine whether ΔABC ≅ ΔKLM given the coordinates of the vertices. A (-3,3), B(-1, 3), C(-3, 1), K(1,4), L(3,4), M(1,6)

10. Example

11. Practice <BAD  <CDA

12. Practice