Questão 2170866

\(n\ r\ \sqrt{2+\cos(\frac{2\pi}{n})}\) .

\(n\ r\ \sqrt{2-2\cos(\frac{2\pi}{n})}\) .

\(n\ r\ \sqrt{2+3\cos(\frac{2\pi}{n})}\) .

\(n\ r\ \sqrt{2-\cos(\frac{\pi}{n})}\) .

\(n\ r\ \sqrt{2-\cos(\frac{2\pi}{n})}\) .