A triangle is a polygon with three corners and three sides, one of the basic shapes in geometry. The corners, also called vertices, are zero-dimensional points while the sides connecting them, also called edges, are one-dimensional See more

Points, lines, and circles associated with a triangle
Each triangle has many special points inside it, on its edges, or otherwise associated with it. … See more

Figures inscribed in a triangle
As discussed above, every triangle has a unique inscribed circle (incircle) that is interior to the triangle … See more

• Ivanov, A.B. (2001) [1994]. "Triangle". Encyclopedia of Mathematics. EMS Press.
• Clark Kimberling: Encyclopedia of triangle centers. Lists some 5200 interesting points associated with any triangle. See more

A triangle is a figure consisting of three line segments, each of whose endpoints are connected. This forms a polygon with three sides and three angles. The terminology for … See more

One way to identify locations of points in (or outside) a triangle is to place the triangle in an arbitrary location and orientation in the Cartesian plane, and to use Cartesian … See more

Circular triangles
A circular triangle is a triangle with circular arc edges. The edges of a circular triangle may be either convex (bending outward) or concave (bending inward). The intersection of three disks forms a circular triangle whose … See more