Why Random Triangles Catch the Circle's Center ¼ of the Time
Drop three random points on a circle and the triangle contains the center exactly a quarter of the time. Two proofs: an honest average, then two coins wearing a geometry costume.
Circle geometry
1 articleAnnulusAntarctic circleApollonian circlesArbelosArchimedean circleArchimedes quadrupletsArctic circleArea of a circleArea of a diskBankoff circleBenz planeBertrand's paradox probabilityBonnesen inequalityBorromean ringsBrahmagupta's formulaBuffon's needleBundle theoremButterfly theoremCasey's theoremCenter pivot irrigationCentral angleCentrifugal forceCentripetal forceChord+ 152 more