Spiegeldreieck

The Fuhrmann triangle of a reference triangle Δ A B C is the triangle Δ F_C F_B F_A formed by reflecting the mid-arc points arc M_A, arc M_B, arc M_C about the lines A B, A C, and B C. The Fuhrmann triangle has trilinear vertex matrix [a | (-a^2 + c^2 + b c)/b | (-a^2 + b^2 + b c)/c (-b^2 + c^2 + a c)/a | b | a^2 - b^2 + a c (b^2 - c^2 + a b)/a | (a^2 - c^2 + a b)/b | c].

circumcircle mid-arc triangle | Fuhrmann center | Fuhrmann circle | mid-arc points