← etc / Encyclopedia of Triangle Centers

X₂₀₂₀¶

EXSIMILICENTER(GALLATLY CIRCLE, APOLLONIUS CIRCLE)

X₂₀₂₀ is the exsimilicenter(gallatly circle, Apollonius circle).

X₂₀₂₀ (EXSIMILICENTER(GALLATLY CIRCLE, APOLLONIUS CIRCLE)) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).¶

"""GEOMETOR construction model for X_2020 = EXSIMILICENTER(GALLATLY CIRCLE, APOLLONIUS CIRCLE)."""

        from __future__ import annotations

        from pathlib import Path

        import sympy.geometry as spg
        from geometor.model import Model

        from geometor.etc.ops import (
            central_line,
            circumcenter_of,
            construct_baseline_triangle,
            create_model,
            eval_trilinear_point,
            promote_point_to_top,
            spieker_center_of,
            symmedian_point_of,
        )
        from geometor.etc.render import write_center_svg


        def construct_x_02020(
            model: Model, A: spg.Point, B: spg.Point, C: spg.Point
        ) -> spg.Point:
            """Construct X_2020 = EXSIMILICENTER(GALLATLY CIRCLE, APOLLONIUS CIRCLE) on reference triangle ABC."""
            X_2020 = eval_trilinear_point(model, A, B, C, '((s**(2) - r**(2))*cos(A) - 2*r*s*sin(A) - (s**(2) + r**(2))*sin(A +  omega  ))', ID="X_2020", classes=["selected", "target"])
            X_3 = circumcenter_of(model, A, B, C, ID="X_3", classes=["center", "incident"])
            X_6 = symmedian_point_of(model, A, B, C, ID="X_6", classes=["center", "incident"])
            central_line(model, X_3, X_6, 3, 6, incident=True)
            X_10 = spieker_center_of(model, A, B, C, ID="X_10", classes=["center", "incident"])
            X_2009 = eval_trilinear_point(model, A, B, C, '(cos(B - C) + sin(A +  omega  ))', ID="X_2009", classes=["center", "incident"])
            central_line(model, X_10, X_2009, 10, 2009, incident=True)
            X_43 = eval_trilinear_point(model, A, B, C, 'a*b + a*c - b*c', ID="X_43", classes=["center", "incident"])
            X_2018 = eval_trilinear_point(model, A, B, C, '(1 + cos(A) - cos(B) - cos(C) - 2*sin(A +  omega  ))', ID="X_2018", classes=["center", "incident"])
            central_line(model, X_43, X_2018, 43, 2018, incident=True)
            return promote_point_to_top(model, X_2020)


        def build_model(
            sides: tuple[float, float, float] = (5.0, 6.0, 7.0),
            show_guides: bool = False,
        ) -> Model:
            """Build a `geometor.model.Model` for X_2020 on the given reference triangle."""
            model = create_model('X_2020 = EXSIMILICENTER(GALLATLY CIRCLE, APOLLONIUS CIRCLE)')
            A, B, C = construct_baseline_triangle(model, *sides, show_guides=show_guides)
            construct_x_02020(model, A, B, C)
            return model


        if __name__ == "__main__":
            here = Path(__file__).resolve().parent
            model_acute = build_model((5.0, 6.0, 7.0))
            model_acute.save(str(here / "x-02020.json"))
            write_center_svg(
                model_acute,
                here / "x-02020.svg",
                subtitle="(a, b, c) = (5, 6, 7) | AB = 1",
            )
        

X2020¶

X₂₀₂₀¶