+118724 1/2pi squareroot(pi*0.0004^2/1000*1.5*(2*10^-13)
enter like this if you want what is below. 
1/2*pi*sqrt((pi*0.0004^2)/(1000*1.5*2*10^-13))
$$\frac{ \pi }{2} \sqrt{\frac{\pi*0.0004^2}{1000*1.5*2*10^{-13}}}$$
You can do this on the site calc on the home page.
