1. Chapter 4

2. Congruent Figures – figures that have exactly the same size and shape.Congruent Figures – figures that have exactly the same size and shape. To check for congruency, you may have to slide, flip, or turn. To check for congruency, you may have to slide, flip, or turn. Congruency Online: Flip, slide and turn…Online: Flip, slide and turn…Online: Flip, slide and turn…Online: Flip, slide and turn…

3. CPCTC: Corresponding Parts of Congruent Triangles are Congruent. Two triangles are congruent if and only if ALL their corresponding parts are congruent. However, we do not have to measure every single part of a triangle to determine if they are congruent… WE CAN USE OUR TRIANGLE POSTULATES!

4. Side–Side–Side Postulate (SSS) If three sides of one triangle are congruent to three sides of another triangle, then the triangles are congruent.

5. Side–Angle–Side Postulate (SAS) If two sides and the included angle of one triangle are congruent to two sides and the included angle of another, then the triangles are congruent.

6. Angle–Side–Angle Postulate (ASA) If two angles and the included side of one triangle are congruent to two angles and the included side of another triangle, then the triangles are congruent.

7. Angle-Angle-Side (AAS) Postulate: If two angles and a non-included side of one triangle are congruent to the corresponding parts of another triangle, then the triangles are congruent

8. Hypotenuse Leg (HL) Postulate: If the hypotenuse and a leg of one right triangle are congruent to the corresponding parts of another right triangle, then the triangles are congruent.

9. Isosceles Triangle Theorem If two sides of a triangle are congruent, then the angles opposite those sides are congruent. Base angles of an isosceles triangle are congruent.

10. If two angles of a triangle are congruent, then the sides opposite those angles are congruent.

11. Altitude of a triangle: Segment that starts at the vertex of a triangle and is perpendicular to the line containing the opposite side of the triangle. Altitude from vertex C. A BC

12. Altitudes in OBTUSE Triangles: Altitude from vertex A. A BC The altitude is OUTSIDE and obtuse triangle !

13. Median Segment whose endpoints are a vertex of a triangle and the midpoint of the opposite side.

14. How to Draw a Median: 1. Find the midpoint using your ruler. 2. Connect the midpoint to the opposite vertex.

15. Angle Bisector of a Triangle A ray that bisects an angle in a triangle.

16. Perpendicular Bisector of a Triangle Segment that passes through the midpoint of and is perpendicular to the side of a triangle.

17. Corollary Corollary: The bisector of the vertex angle of an isosceles triangle is perpendicular to the base at its midpoint.

18. Homework Pg 628 –1-12 all Pg 629 –1-14all