A calculus problem by Kaleem Kħặŋ

Using the gamma function: $(0.5)!=\Gamma \left( \frac { 3 }{ 2 } \right) =\int _{ 0 }^{ \infty }{ \frac { \sqrt { x } }{ { e }^{ x } } } dx=\frac { \sqrt { \pi } }{ 2 }$ I won't go into the details of this calculation but here's the calculation of the integral from a calculator. Anyway, from here, ${ \left((0.5)!\times 2\right) }^{ 2 }={ \left( \frac { \sqrt { \pi } }{ 2 } \times 2 \right) }^{ 2 }=\pi$ and we're done.