lean_workbook_plus_4774

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by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

and from formula: $\triangle=\frac{1}{2}\cdot bc \cdot \sin \alpha \implies 4\triangle =2bc\sin \alpha \implies 16 \triangle ^2=4b^2c^2 \cdot \sin^2 \alpha$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_4774 : ∀ b c : ℝ, ∀ α : ℝ, (α ≠ 0 ∧ α ≠ π) → 16 * (1 / 2 * b * c * Real.sin α) ^ 2 = 4 * b ^ 2 * c ^ 2 * (Real.sin α) ^ 2   :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook

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