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 ~
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