olymmath

IMO 1985 Problem 1

  • Day 1

A circle has center on the side ABAB of the cyclic quadrilateral ABCDABCD . The other three sides are tangent to the circle. Prove that AD+BC=ABAD+BC=AB .

Official text Transcription from AI-MO AoPS, checked word for word against the official paper. Quoted with source.

Official text: IMO 1985 official English paper, page 1.

Solutions

No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.

Add a solution

Locator imo/1985/p1 · Tag JPCNKZ434Z · Edit this page on GitHub · Keys: j next, k previous