Triangle geometry

idea in geometry

coordinate system in which the location of a point of a simplex is specified as the center of mass, or barycenter, of usually unequal masses placed at its vertices

given a point P and a triangle ABC, the point constructed by reflecting the lines PA, PB, and PC about the angle bisectors of A, B, and C respectively

In geometry, the semiperimeter of a polygon is half its perimeter. Although it has such a simple derivation from the perimeter, the semiperimeter appears frequently enough in formulas for triangles and other figures that it is given a separate name. When the semiperimeter occurs as part of a formula, it is typically denoted by the letter .

coordinate system based on a triangle

theorem that, in Euclidean geometry, the sum of angles of a triangle is π radians

positive integer that is the area of a right triangle with three rational number sides

concept in geometry

two figures in a plane are perspective from a point O if the lines joining corresponding points of the figures all meet at O

geometric theorem regarding 3 circles intersecting at a point

division of a surface into triangles

set of integers, the lengths of the sides of a triangle with a 60° angle

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triangle geometry

unique curve associated with every triangle

plane curve associated with any triangle

method of calculating ray-triangle intersections in 3D space