π 12 = π 2 ⋅ 6 ⋅ 180 ∘ π = π 2 ⋅ 6 ⋅ 2 ⋅ 2 ⋅ 5 ⋅ 3 ⋅ 3 ⋅ π = 90 c i r c 6 = 15 c i r c {\displaystyle {\frac {\pi }{12}}={\frac {\pi }{2\cdot 6}}\cdot {\frac {180^{\circ }}{\pi }}={\frac {\cancel {\pi }}{{\cancel {2}}\cdot {6}}}\cdot {\frac {{\cancel {2}}\cdot {2}\cdot {5}\cdot {3}\cdot {3}\cdot }{\cancel {\pi }}}={\frac {90^{circ}}{6}}={15^{circ}}}
