incircle


The incircleMathworldPlanetmath or inscribed circle of a triangle is a circle interior to the triangle and tangent to its three sides.

Moreover, the incircle of a polygonMathworldPlanetmathPlanetmath is an interior circle tangent to all of the polygon’s sides. Not every polygon has an inscribed circle, but triangles always do.

The center of the incircle is called the incenterMathworldPlanetmath, and it’s located at the point where the three angle bisectorsMathworldPlanetmath intersect.

If the sides of a triangle are x, y and z, the area A and the semiperimeter p, then the radius of incircle may be calculated from

r=2Ax+y+z=Ap=(p-x)(p-y)(p-z)p.
Title incircle
Canonical name Incircle
Date of creation 2013-03-22 12:11:09
Last modified on 2013-03-22 12:11:09
Owner drini (3)
Last modified by drini (3)
Numerical id 8
Author drini (3)
Entry type Definition
Classification msc 51M99
Related topic LemoinePoint
Related topic Incenter
Related topic LemoineCircle
Related topic Triangle
Related topic GergonnePoint
Related topic GergonneTriangle
Related topic ConstructionOfTangent