If a points ,
, and are marked on each side of a triangle , one on each side (or on a side's
extension), then the three Miquel circles (each
through a polygon vertex and the two marked points
on the adjacent sides) are concurrent at a point called the Miquel
point. This result is a slight generalization of the so-called pivot
theorem.
If
lies in the interior of the triangle, then it satisfies
(1)
(2)
(3)
The lines from the Miquel point to the marked points make equal angles with the respective sides. (This is a by-product of the Miquel
equation.)
A generalized version of Miquel's theorem states that given four lines , ..., each intersecting the other
three, the four Miquel circles passing through
each subset of three intersection points of the lines meet in a point known as the
4-Miquel point .
Furthermore, the centers of these four Miquel circles
lie on a circle (Johnson 1929, p. 139). The lines from to given points on the sides make equal angles
with respect to the sides.
Moreover, given
lines taken by s
yield Miquel circles like passing through a point , and their centers lie on a circle .