Miquel's theorem was named after Auguste Miquel. It concerns the intersection of three circles, all drawn through one vertex of a triangle and two points on its adjacent sides. It's one of several results concerning circles in Euclidean geometry.
Notice how the Miquel point (yellow point) changes when the F point moves.After watching the animation pause it and play around with the points, you can move the points around or make the triangle bigger or smaller and see how it affects the Miquel point.