1. Do Now Are triangles ABC and DEF congruent? A(-2,-2) B(4,-2) C(4,6) and D(5,7) E(5,1) F(13,1) –What types of lines make up the triangle?

2. Congruence How do we know if triangles are congruent? What do we need to know about the triangles in order to be able to assume they are congruent?

3. Side Angle Side Congruence Postulate If two sides and the included angle of one triangle are congruent to two sides and the included angle of a second triangle, then the two triangles are congruent.

4. Right Triangles Can we assume that the triangles are congruent? Why?

5. Hypotenuse Leg Congruence Theorem If the hypotenuse and a leg of a right triangle are congruent to the hypotenuse and a leg of a second right triangle, then the two triangles are congruent.

6. Given: WY congruent to XZ, WZ perp. To ZY, and XY perp. To ZY Prove: Triangles WYZ and XZY are congruent WY congruent to XZ WZ perp. ZY, XY perp. ZY Angles Z and Y are right Triangles WYZ and XZY are right triangles ZY congruent to YZ Triangles WYZ and XZY are congruent.

7. Given: WY congruent to XZ, WZ perp. To ZY, and XY perp. To ZY Prove: Triangles WYZ and XZY are congruent WY congruent to XZ WZ perp. ZY, XY perp. ZY Angles Z and Y are right Triangles WYZ and XZY are right triangles ZY congruent to YZ Triangles WYZ and XZY are congruent. Given Def of Perpendicular Def of a right Triangle Reflexive Prop. Of Congruence HL Congruence Thm