Toolkit 58Law of CosinesFor a triangle with sides aaa, bbb, ccc:a2=b2+c2−2bccosAa^2=b^2+c^2-2bc\cos Aa2=b2+c2−2bccosAorcosA=b2+c2−a22bc\cos A=\frac{b^2+c^2-a^2}{2bc}cosA=2bcb2+c2−a2Related ProblemsCoreAMC 12A 2024 (Problem 19)AMC 12A 2022 (Problem 12)AMC 12A 2025 (Problem 8)MajorAMC 12A 2025 (Problem 24)AMC 12B 2025 (Problem 21)AMC 12B 2025 (Problem 25)
