# First Fermat Point and Isogonic Center of a Triangle

First Fermat Point and Isogonic Center of a Triangle

This Demonstration plots the first Fermat point (red) and first isogonic center (yellow) of a triangle . You can drag the triangle vertices. When and are both inside the triangle, they coincide.

FFP

FIC

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FFP

FIC

Let be the sum of the distances from a point to the three vertices of . Then minimizes . The contours show the level lines of .

F(P,T)

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T

FFP

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F