1. Math presentation About “ CONGRUENCE ” By : Rizaldi Pahlevi and Abel Agusta Banuboro

4. Congruent Triangles

6. Corresponding parts of congruent triangles If Δ ABC is congruent to Δ XYZ , then vertices of the two triangles correspond in the same order as the letter naming the triangles. A C B X Z Y Δ ABC = Δ XYZ ~

7. Corresponding parts of congruent triangles This correspondence of vertices can be used to name the corresponding congruent sides and angles of the two triangles. A C B X Z Y Δ ABC = Δ XYZ ~

11. CONDITIONS for CONGRUENCE of TWO TRIANGLE

14. The angle between two sides Included Angle  G  I  H

15. Name the included angle: Y E and E S E S and Y S Y S and Y E Included Angle S Y E  E  S  Y

17. The side between two angles Included Side GI HI GH

18. Name the included angle :  Y and  E  E and  S  S and  Y Included Side YE ES SY S Y E

20. Warning: No SSA Postulate A C B D E F NOT CONGRUENT There is no such thing as an SSA postulate!

21. Warning: No AAA Postulate A C B D E F There is no such thing as an AAA postulate! NOT CONGRUENT

22. CONDITIONS for SIMILARITY of TWO TRIANGLE

23. All the corresponding sides of the two triangles are PROPORTIONAL 1. A C B P R Q AB PQ BC QR AC PR = =

24. 2. Two angles of one triangle are equal in measure to two corresponding angles of the other triangle. A b c g h i

25. 3. A b c D E F An angle of one triangle is equal in measure to an angle of the other triangle, and the sides which include the equal angle of both triangles are proportional

26. The formulas for a right triangle with altitude on the hypotenuse A B C AD 2 = BD X CD AB 2 = BD X BC D AC 2 = CD X CB

27. The formulas for a triangle containing a line parallel to one of its sides A B C D E a b c d e f = = = = = = > > Cd ca Ce cb De ab a a+b C c+d e f a b c d a c b d