Monge's Circle Theorem
Calculus & Analysis
About Monge's Circle Theorem
Explore three-circle tangent intersections, homothety centers and their collinear Monge line, including nested circles and points at infinity.
For three circles of unequal radii with two distinct common external tangents for every pair, the three intersections of those tangent pairs lie on one straight line. This is Gaspard Monge's circle theorem. A tangent is external here when the circle centers lie on the same side of the tangent line; this is different from two circles being externally tangent to each other.
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