Category:Sum of Cosines of Angles in Triangle

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This category contains pages concerning Sum of Cosines of Angles in Triangle:


Let $\triangle ABC$ be a triangle.

Then:

$\cos A + \cos B + \cos C = 1 - 4 \sin \dfrac A 2 \sin \dfrac B 2 \sin \dfrac C 2$

Pages in category "Sum of Cosines of Angles in Triangle"

The following 2 pages are in this category, out of 2 total.