The Law of Cosines - Yet Another PWW
John Molokach got a featured proof without words in The American Mathematical Monthly (Vol. 121, No. 8, October 2014):
$a=b\cos C+c\cos B\\ b=c\cos A+a\cos C\\ c=a\cos B+b\cos A\\ c^{2}=ac\cos B+bc\cos A\\ c^{2}=a(a-b\cos C)+b(b-a\cos C)\\ c^{2}=a^{2}-2ab\cos C+b^{2}.$
- The Law of Cosines (Cosine Rule)
- The Illustrated Law of Cosines
- The Law of Sines and Cosines
- The Law of Cosines: Plane Tessellation
- The Law of Cosines: after Thâbit ibn Qurra
- The Law of Cosines: Unfolded Version
- The Law of Cosines (Independent of the Pythagorean Theorem)
- The Cosine Law by Similarity
- The Law of Cosines by Larry Hoehn
- The Law of Cosines - Another PWW
- The Law of Cosines - Yet Another PWW
- Law of Cosines by Ancient Sliding
- The Cosine Law: PWW by S. Kung
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