(In reply to discussion
Generally speaking, I liked your presentation.
However, there are two small points I would like to raise:
a) You forgot to mention that r=rho.
b) Presenting so many digits implies accuracy, while the whole calculation is location dependant: rho is between 6356 km (at the poles) and 6378 km (equator), and since in the equation it appears squared the the error might be over 5%.
So why go over two decimal places after the decimal point?