Triangle -- from Wolfram MathWorld

A triangle is a 3-sided polygon sometimes (but not very commonly) called the trigon. Every triangle has three sides and three angles, some of which may be the same. The sides of a triangle are given special names in the case of a right triangle, with the side opposite the right angle being termed the hypotenuse and the other two sides being known as the legs. All triangles are convex and bicentric. That portion of the plane enclosed by the triangle is called the triangle interior, while the

Magog Triangle -- from Wolfram MathWorld

Dual Tessellation -- from Wolfram MathWorld

Equilateral Triangle -- from Wolfram MathWorld

Catalan's Triangle -- from Wolfram MathWorld

Triangle Area -- from Wolfram MathWorld

Medial Triangle -- from Wolfram MathWorld

Circumtangential Triangle -- from Wolfram MathWorld

Spherical Coordinates -- from Wolfram MathWorld

Mathworld - Wolfram.com LegendreDifferentialEquation PDF

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Pythagorean Triangle -- from Wolfram MathWorld

geometry - Coordinates of parallel triangle with a distance of 'd

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