1. 1 Press Ctrl-A ©G Dear2010 – Not to be sold/Free to use CongruentTriangles Stage 4 - Year 9

2. They are congruent Two triangles are congruent if they are the same size and shape. Click End of Slide

3. They are not congruent Two triangles are not congruent if they are not the same size and shape. Click End of Slide

4. Two triangles are congruent if they are the same size and shape. End of Slide There are four Rules Side, Side, Side. Side, Angle, Side. Angle, Angle, Side. Right Angle, Hypotenuse, Side. Click on one of the rules above.

5. Click End of Slide 1 S ide, S ide, S ide. The 3 sides of one triangle equal the 3 sides of the other triangle. A BC D EF Proof for SSS AB = DE (Side) BC = EF (Side) AC = DF (Side) D EF   ABC   DEF (SSS) is congruent to

6. End of Slide 1 S ide, S ide, S ide. The 3 sides of one triangle equal the 3 sides of the other triangle. A BC D EF Proof for SSS AB = DE (Side) BC = EF (Side) AC = DF (Side) 4cm 6cm 7cm   ABC   DEF (SSS) is congruent to

7. Click End of Slide 2 S ide, A ngle, S ide. 2 sides & included angle of one triangle equal those of the other triangle. A BC D EF Proof for SAS AB = DE (Side) BC = EF (Side)  B =  E (Included Angle) D EF   ABC   DEF (SAS) is congruent to

8. End of Slide 2 S ide, A ngle, S ide. 2 sides & included angle of one triangle equal those of the other triangle. A BC D EF Proof for SAS AB = DE (Side) BC = EF (Side)  B =  E (Included Angle) 4cm 6cm 60 o   ABC   DEF (SAS) is congruent to

9. Click End of Slide 3 A ngle, A ngle, S ide. 2 angles & corresponding side of one triangle equal those of the other triangle. A BC D EF Proof for AAS  A =  D (Angle) AB = DE (Side)  B =  E (Angle) D EF   ABC   DEF (AAS) is congruent to

10. 60 o End of Slide 3 A ngle, A ngle, S ide. 2 angles & corresponding side of one triangle equal those of the other triangle. A BC D EF Proof for AAS  A =  D (Angle) AB = DE (Side)  B =  E (Angle) 62 o 4cm   ABC   DEF (AAS) is congruent to

11. Click End of Slide 3 R ight-angle, H ypotenuse, S ide. The right-angle, hypotenuse & corresponding side of one triangle equal those of the other. Proof for RHS  B =  E (Right-angle) AB = DE (Side) AC = DF (Hypotenuse) A BC D EF D EF   ABC   DEF (RHS) is congruent to

12. End of Slide 3 R ight-angle, H ypotenuse, S ide. The right-angle, hypotenuse & corresponding side of one triangle equal those of the other. Proof for RHS  B =  E (Right-angle) AB = DE (Side) AC = DF (Hypotenuse) A BC D EF 4cm 5cm   ABC   DEF (RHS) is congruent to