Coordinate system based on distances from the sidelines of a given triangle
In geometry, the trilinear coordinatesx : y : z of a point relative to a given triangle describe the relative directed distances from the three sidelines of the triangle. Trilinear coordinates are an example of homogeneous coordinates. The ratio x : y is the ratio of the perpendicular distances from the point to the sides (extended if necessary) opposite vertices A and B respectively; the ratio y : z is the ratio of the perpendicular distances from the point to the sidelines opposite vertices B and C respectively; and likewise for z : x and vertices C and A.
In the diagram at right, the trilinear coordinates of the indicated interior point are the actual distances (a', b', c'), or equivalently in ratio form, ka' : kb' : kc' for any positive constant k. If a point is on a sideline of the reference triangle, its corresponding trilinear coordinate is 0. If an exterior point is on the opposite side of a sideline from the interior of the triangle, its trilinear coordinate associated with that sideline is negative. It is impossible for all three trilinear coordinates to be non-positive.
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In geometry, the trilinearcoordinates x : y : z of a point relative to a given triangle describe the relative directed distances from the three sidelines...
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homogeneous coordinates (1 : i : 0) and (1 : −i : 0). Let A. B. C be the measures of the vertex angles of the reference triangle ABC. Then the trilinear coordinates...
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are tetrahedra (3D simplices), then barycentric coordinates provide a straightforward procedure. Trilinear interpolation is frequently used in numerical...
|AN|^{2}+|BL|^{2}+|CM|^{2}=|NB|^{2}+|LC|^{2}+|MA|^{2}.} If P has trilinearcoordinates p : q : r, then the vertices L, M, N of the pedal triangle of P...
are the side-lengths of a reference triangle then the point whose trilinearcoordinates are f ( a , b , c ) : f ( b , c , a ) : f ( c , a , b ) {\displaystyle...
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Centers the circle E is the called the Apollonius circle of △ABC. The trilinearcoordinates of the Apollonius point are a ( b + c ) 2 b + c − a : b ( c + a...
therefore the ratio of weights at A and C being α : γ. In trilinearcoordinates, a point with coordinates x :y :z has perpendicular distances to side BC (across...
reference triangle △ABC. Let the trilinearcoordinates of the point P be p : q : r. Then the trilinear equation of the trilinear polar of P is x p + y q + z...
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ternary plot correspond (up to a constant) to its trilinearcoordinates or barycentric coordinates. There are three equivalent methods that can be used...
three constructed equilateral triangles are concurrent at X(13). Trilinearcoordinates for the first isogonic center, X(13): csc ( A + π 3 ) : csc ...
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is the reflection of triangle ABC in the Gossard perspector. The trilinearcoordinates of the Gossard perspector of triangle ABC are ( f ( a, b, c ) :...
the reference triangle, and let x : y : z be a variable point in trilinearcoordinates; then an equation for the Euler line is sin ( 2 A ) sin ( B...
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and having endpoints on these sidelines have equal lengths. The trilinearcoordinates of the equal parallelians point of triangle △ABC are b c ( c a +...