11 ms·

A million square metres is one square kilometre. It could be built but it would be heavy. A circular sail with a radius of just over 600 metres would do it.

• chasd00 6y ago
  wouldn't a million square metered be a megametre and not kilometre?
  • codeduck 6y ago
    no. 1000m * 1000m = 1000000m^2 or 1 km^2