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X₃₆₀₁¶

INTERSECTION OF LINES X₁X_3 AND X₉X_21

X₃₆₀₁, the {X₁, X₃₆₁₁}-harmonic conjugate of X₃₅₇₆, was found by Peter Moses in connection with the 1st Liu point.

X₃₆₀₁ (INTERSECTION OF LINES X₁X_3 AND X₉X_21) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).¶

"""GEOMETOR construction model for X_3601 = INTERSECTION OF LINES X_1X_3 AND X_9X_21."""

        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,
            incenter_of,
            mittenpunkt_of,
            promote_point_to_top,
        )
        from geometor.etc.render import write_center_svg


        def construct_x_03601(
            model: Model, A: spg.Point, B: spg.Point, C: spg.Point
        ) -> spg.Point:
            """Construct X_3601 = INTERSECTION OF LINES X_1X_3 AND X_9X_21 on reference triangle ABC."""
            X_3601 = eval_trilinear_point(model, A, B, C, '3*cos(A) + cos(B) + cos(C) + 1', ID="X_3601", classes=["selected", "target"])
            X_1 = incenter_of(model, A, B, C, ID="X_1", classes=["center", "incident"])
            X_3 = circumcenter_of(model, A, B, C, ID="X_3", classes=["center", "incident"])
            central_line(model, X_1, X_3, 1, 3, incident=True)
            X_9 = mittenpunkt_of(model, A, B, C, ID="X_9", classes=["center", "incident"])
            X_21 = eval_trilinear_point(model, A, B, C, '1/(cos(B) + cos(C))', ID="X_21", classes=["center", "incident"])
            central_line(model, X_9, X_21, 9, 21, incident=True)
            X_28 = eval_trilinear_point(model, A, B, C, '(tan(A))/(b + c)', ID="X_28", classes=["center", "incident"])
            X_33 = eval_trilinear_point(model, A, B, C, '1 + sec(A)', ID="X_33", classes=["center", "incident"])
            central_line(model, X_28, X_33, 28, 33, incident=True)
            return promote_point_to_top(model, X_3601)


        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_3601 on the given reference triangle."""
            model = create_model('X_3601 = INTERSECTION OF LINES X_1X_3 AND X_9X_21')
            A, B, C = construct_baseline_triangle(model, *sides, show_guides=show_guides)
            construct_x_03601(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-03601.json"))
            write_center_svg(
                model_acute,
                here / "x-03601.svg",
                subtitle="(a, b, c) = (5, 6, 7) | AB = 1",
            )
        

X3601¶

X₃₆₀₁¶