1. Section 4.2 Congruence and Triangles

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

4. Congruent Triangles Triangles that have Corresponding angles congruent and corresponding sides congruent

5. Same position Corresponding Sides

6. Corresponding Angles Same position

7. Third Angle Theorem If two angles of one triangle are to two angles of a second triangle, then the third pair of angles have to be congruent.

8. A B C D E F Ex 1: Write a congruence statement for the triangles. List all congruent sides and angles

9. Ex 2: Solve for x and y. G L M E P F H N 72 o 87 o 110 o 8m 10m (2x – 3)m (7y+9) o

10. Ex 3: Solve for x. T L M S R N 65 o 55 o (2x +30) o

11. Ex 4: Are these two triangles congruent? Explain. P Q M N R 92 o Sides: Angles: (given) (vertical angles) (3 rd angles thm) Yes, they are congruent because all sides and angles are congruent

12. Guided Practice p. 205 #1-9 Find a partner for Think, pair, share!!!