Category
page 1Theorems about triangles and circles
Thales' theorem
theorem
Carnot's theorem
theorem about the sum of the distances from the circumcenter to the sides of an arbitrary triangle
Euler's theorem in geometry
theorem describing distance between circumcentre and incentre of a triangle
Miquel's theorem
theorem in geometry about three circles through triples of points on the vertices and sides of a triangle
Pompeiu's theorem
Japanese theorem for cyclic polygons
theorem that no matter how one triangulates a cyclic polygon, the sum of inradii of triangles is constant
Lester's theorem
theorem
Thébault's theorem
one of three theorems in geometry proved by French mathematician Victor Thébault
trillium theorem
a statement about properties of inscribed and circumscribed circles
Reuschle's theorem
describes a property of the cevians of a triangle intersecting in a common point
Feuerbach point
result on the incircle and nine-point circle of a triangle and the three excircles
Kosnita Point
concurrency of lines connecting to certain circles associated with an arbitrary triangle
van Schooten's theorem
property of equilateral triangles
Conway circle
geometrical construction based on extending the sides of a triangle
Equal incircles theorem
on rays from a point to a line, with equal inscribed circles between adjacent rays
Musselman's theorem
About a common point of certain circles defined by an arbitrary triangle
Harcourt's theorem
formula for the area of a triangle