Explicație pas cu pas:
[tex]\angle A = \angle B = \frac{\pi}{6} = 30 \degree \\[/tex]
[tex]\angle C = 180 \degree - 2 \cdot 30 \degree = 180 \degree - 60 \degree = 120 \degree[/tex]
[tex]2R = \frac{AB}{\sin(\angle C)} = \frac{3}{\sin(120 \degree)} \\ R = \frac{3}{2 \cdot \cos(30 \degree)} = \frac{3}{2 \cdot \frac{ \sqrt{3} }{2} } = \frac{3}{ \sqrt{3} } = \frac{3 \sqrt{3} }{3} \\ \implies \bf R = \sqrt{3} [/tex]
