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Right Triangles Ladder

Who This Is For

Use this ladder when you already trust your geometry primitives and want to practice the first strong counting-geometry pattern: normalize directions and count perpendicular structure.

Warm-Up

  • direction normalization
  • perpendicular direction pairing

Core

  • anchor one point and count valid angle pairs
  • avoid floating-point slopes

Example Notes

Exit Criteria

You are ready to move on when you can:

  • normalize directions with one stable sign convention
  • count right-angle configurations without brute-forcing triples
  • explain why integer normalization beats floating-point slope comparison
  • connect the note back to Counting Geometry

External Practice