EntityQ2981012· pop 14· linked from 10 articlesMonge's theoremSign in to savetheorem that the intersections of the 3 pairs of external tangent lines to 3 circles are collinearConnectionsgeometryEntityInternational Standard Book NumberEntitytangentEntityGaspard MongeEntityMenelaus' theoremEntityMathWorldEntitycollinearityEntityDesargues' theoremEntityProblem of ApolloniusEntityprojective planeEntitypoint at infinityEntity3Blue1BrownEntityTangent lines to circlesEntityhomothetic centerEntityAlexander BogomolnyEntityCategoriesEuclidean plane geometryTheorems about circles