在平面上绘制三个圆，其中任何一个圆都没有完全包含在另一个圆内，并绘制每对圆的公外切线。然后，三对切线的交点位于一条直线上。
蒙日圆定理有一个三维类比，它指出由四个球体（每次取两个）定义的圆锥的顶点位于一个平面上（当圆锥在球体的顶点同一侧绘制时；Wells 1991）。
蒙日圆定理
另请参阅
圆-圆 切线， 圆 切线使用 Wolfram|Alpha 探索
参考文献
Bogomolny, A. "Three Circles and Common Tangents." http://www.cut-the-knot.org/proofs/threecircles.shtml.Bogomolny, A. "Monge via Desargues." http://www.cut-the-knot.org/Curriculum/Geometry/MongeTheorem.shtml.Bogomolny, A. "Monge via Desargues II." http://www.cut-the-knot.org/Curriculum/Geometry/MongeDesargues.shtml.Coxeter, H. S. M. "The Problem of Apollonius." Amer. Math. Monthly 75, 5-15, 1968.Graham, L. A. Problem 62 in Ingenious Mathematical Problems and Methods. New York: Dover, 1959. Ogilvy, C. S. Excursions in Geometry. New York: Dover, pp. 115-117, 1990.Petersen, J. Methods and Theories for the Solution of Problems of Geometrical Constructions, Applied to 410 Problems. London: Sampson Low, Marston, Searle & Rivington, pp. 92-93, 1879.Walker, W. "Monge's Theorem in Many Dimensions." Math. Gaz. 60, 185-188, 1976.Wells, D. The Penguin Dictionary of Curious and Interesting Geometry. London: Penguin, pp. 153-154, 1991.在 Wolfram|Alpha 中被引用
蒙日圆定理请引用为
Weisstein, Eric W. "蒙日圆定理。" 来自 MathWorld--Wolfram Web 资源。 https://mathworld.net.cn/MongesCircleTheorem.html