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X₃₃₈₁¶

SEC(A - π/5) POINT

X₃₃₈₁ and related points occupy Bernard Gibert’s Table 38. See the note at X₃₃₆₄.

X₃₃₈₁ (SEC(A - π/5) POINT) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\).¶

"""GEOMETOR construction model for X_3381 = SEC(A - π/5) 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,
            isogonal_conjugate,
            promote_point_to_top,
        )
        from geometor.etc.render import write_center_svg


        def construct_x_03381(
            model: Model, A: spg.Point, B: spg.Point, C: spg.Point
        ) -> spg.Point:
            """Construct X_3381 = SEC(A - π/5) POINT on reference triangle ABC."""
            X_3379 = eval_trilinear_point(model, A, B, C, '(cos(A -  pi  /5))', ID="X_3379", classes=["center"])
            X_3381 = isogonal_conjugate(model, A, B, C, X_3379, ID="X_3381", classes=["selected", "target"])
            X_1140 = eval_trilinear_point(model, A, B, C, '(csc(A))/(cot(A) - cot(2*pi/5))', ID="X_1140", classes=["center", "incident"])
            X_3368 = eval_trilinear_point(model, A, B, C, '(cos(A - 2*pi  /5))', ID="X_3368", classes=["center", "incident"])
            central_line(model, X_1140, X_3368, 1140, 3368, incident=True)
            X_1139 = eval_trilinear_point(model, A, B, C, '(csc(A))/(cot(A) + cot(2*pi/5))', ID="X_1139", classes=["center", "incident"])
            central_line(model, X_1139, X_3379, 1139, 3379, incident=True)
            X_3369 = eval_trilinear_point(model, A, B, C, '(sin(A - 2*pi  /5))', ID="X_3369", classes=["center", "incident"])
            X_3370 = eval_trilinear_point(model, A, B, C, '(sec(A - 2*pi  /5))', ID="X_3370", classes=["center", "incident"])
            central_line(model, X_3369, X_3370, 3369, 3370, incident=True)
            return promote_point_to_top(model, X_3381)


        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_3381 on the given reference triangle."""
            model = create_model('X_3381 = SEC(A - π/5) POINT')
            A, B, C = construct_baseline_triangle(model, *sides, show_guides=show_guides)
            construct_x_03381(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-03381.json"))
            write_center_svg(
                model_acute,
                here / "x-03381.svg",
                subtitle="(a, b, c) = (5, 6, 7) | AB = 1",
            )
        

X3381¶

X₃₃₈₁¶