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X₉₇₃¶

1st EHRMANN POINT

X₉₇₃ = X₄₄₂-of-orthic-triangle if ABC is acute

X₉₇₃ (1st EHRMANN POINT) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).¶

"""GEOMETOR construction model for X_973 = 1st EHRMANN POINT."""

        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,
            construct_baseline_triangle,
            create_model,
            eval_trilinear_point,
            intersect_lines,
            nine_point_center_of,
            promote_point_to_top,
            symmedian_point_of,
        )
        from geometor.etc.render import write_center_svg


        def construct_x_00973(
            model: Model, A: spg.Point, B: spg.Point, C: spg.Point
        ) -> spg.Point:
            """Construct X_973 = 1st EHRMANN POINT on reference triangle ABC."""
            X_6 = symmedian_point_of(model, A, B, C, ID="X_6", classes=["center"])
            X_24 = eval_trilinear_point(model, A, B, C, 'sec(A)*cos(2*A)', ID="X_24", classes=["center"])
            X_5 = nine_point_center_of(model, A, B, C, ID="X_5", classes=["center"])
            X_51 = eval_trilinear_point(model, A, B, C, 'a**(2)*cos(B - C)', ID="X_51", classes=["center"])
            central_line(model, X_6, X_24, 6, 24)
            central_line(model, X_5, X_51, 5, 51)
            X_973 = intersect_lines(model, X_6, X_24, X_5, X_51, ID="X_973", classes=["selected", "target"])
            X_68 = eval_trilinear_point(model, A, B, C, 'cos(A)*sec(2*A)', ID="X_68", classes=["center", "incident"])
            X_568 = eval_trilinear_point(model, A, B, C, 'a*(3*R**(2)*(b**(2) + c**(2) - a**(2)) + a**(2)*b**(2) + a**(2)*c**(2) - b**(4) - c**(4))', ID="X_568", classes=["center", "incident"])
            central_line(model, X_68, X_568, 68, 568, incident=True)
            return promote_point_to_top(model, X_973)


        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_973 on the given reference triangle."""
            model = create_model('X_973 = 1st EHRMANN POINT')
            A, B, C = construct_baseline_triangle(model, *sides, show_guides=show_guides)
            construct_x_00973(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-00973.json"))
            write_center_svg(
                model_acute,
                here / "x-00973.svg",
                subtitle="(a, b, c) = (5, 6, 7) | AB = 1",
            )
        

X973¶

X₉₇₃¶