Junior Cycle · Geometry Lesson 5 of 12

JCHL Geometry 5: Congruent Triangles

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Learning work

  • Congruent = the exact same triangle (all 3 sides AND all 3 angles equal)
  • Four ways to prove it: SSS, SAS, ASA, RHS — each needs THREE matching facts
  • AAA (all angles equal) is NOT congruent — that is only SIMILAR
  • In a proof, every statement must be justified (given / common side / alternate angles / etc.)

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