isosceles triangle

An isosceles triangleMathworldPlanetmath is a triangle with two congruent sides. The angles opposite these two sides are the base angles and the angle between those sides is the vertex angle of the triangle.

This definition implies that any equilateral triangleMathworldPlanetmath is isosceles too, but there are isosceles triangles that are not equilateral.

In any isosceles triangle, the angles opposite to the congruent sides are also congruent. In fact, this condition could be used to give an alternate definition of isosceles, since a triangle is isosceles if and only if it has two congruent angles.

In an equilateral triangle, the height (, the median and the bisectorMathworldPlanetmath to the third side are the same line.

Title isosceles triangle
Canonical name IsoscelesTriangle
Date of creation 2013-03-22 11:44:12
Last modified on 2013-03-22 11:44:12
Owner drini (3)
Last modified by drini (3)
Numerical id 17
Author drini (3)
Entry type Definition
Classification msc 51-00
Classification msc 49J20
Classification msc 49J30
Classification msc 49-01
Synonym isosceles
Related topic Triangle
Related topic RightTriangle
Related topic EquilateralTriangle
Related topic EquivalentConditionsForTriangles
Related topic EquiangularTriangle
Related topic RegularTriangle
Defines base angle
Defines vertex angle