Basic Geometry Proving Triangle Congruence – NOTES 1/28/13 Two shapes are congruent if: 1) _______________ of the corresponding _____________ are congruent 2) ________________ of the corresponding _____________ are congruent

Side-Side-Side

Side: _______ ≅ _______

Side:_______ ≅ _______

Side:_______ ≅ _______

Δ _______ ≅ Δ _______

Side-Angle-Side

Side: _______ ≅ _______

Angle: _______ ≅ _______

Side:_______ ≅ _______

Δ _______ ≅ Δ _______

Angle-Side-Angle

Angle: _______ ≅ _______

Side: _______ ≅ _______

Angle:_______ ≅ _______

Δ _______ ≅ Δ _______

Angle-Angle-Side

Angle: _______ ≅ _______

Angle: _______ ≅ _______

Side:_______ ≅ _______

Δ _______ ≅ Δ _______

Basic Geometry Proving Triangle Congruence – NOTES 1/28/13 Proving Triangles are Congruent - STEPS 1) Mark any more _______________ or ________________ that are ________________________.

2) Pick a method (SSS, SAS, ASA, AAS)

3) List the corresponding ____________________ parts

4) State which triangles are congruent

Prove the triangles are congruent 1) Congruent Triangles: 2) Congruent Triangles: 3) Congruent Triangles:

Basic Geometry Proving Triangle Congruence – NOTES 1/28/13 29. You can use the method described to approximate the distance across a stream without getting wet. a) From the description of the measuring method, what corresponding parts of the two triangles can you

assume are congruent?

b) What theorem or postulate can be used to show that the two triangles are congruent?

c) Explain why the length of BD is also the distance across the stream.