− π 2 {\displaystyle {\frac {{\cancel {-}}\pi }{\cancel {2}}}} ⋅ {\displaystyle \cdot } 2 ⋅ 2 ⋅ 5 ⋅ 3 ⋅ 3 π {\displaystyle {\frac {{\cancel {2}}\cdot 2\cdot 5\cdot 3\cdot 3}{\cancel {\pi }}}}
