you just discovered its circumference, that is the input.
I think the problem should be called 'surface AREA' of a spherical planet.
:P
I need to remember that using 0.31830988618379067154 is less expensive (size 14) than using 1/pi (size 15) ;)
Yeah. But this is useful only within Cody. For real work it would be crazy to program it this way.
Only if you are writing for a low solution size. There's on penalty for writing for clarity, and it's preferred in the real world...