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Overview

USAMO geometry emphasizes constructions and clean arguments. Inversion and homography can simplify tough configurations.

Key Ideas

  • Inversion maps lines and circles to lines and circles.
  • Projective transformations preserve cross ratios and collinearity.
  • Auxiliary points often reveal similarity or power of a point.

Practice Problems

StatusSourceProblem NameDifficultyTags
USAMOInsane
Show TagsGeometry, Inversion
USAMOVery Hard
Show TagsGeometry

Module Progress:

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