π 2 ∘ ⋅ 180 π ∘ = π 2 = 2 π 3 {\displaystyle {\frac {\pi }{2}}^{\circ }\cdot {\frac {180}{\pi {\circ }}}={\frac {\pi }{2}}^{=}{\frac {2\pi }{3}}}
