>I'm standing outside. I would have to guess at the height of the clouds, but is there a basic calculation to tell me how far away, by land, that cloud is? Is it simply a2 + b2 = c2? Not counting for the curvature of the earth? I think kind of yes, but since I'm only guessing at the height of the cloud (a2), and I don't know the distance on land from where I'm standing to directly underneath the cloud (b2) and I sure don't know the distance I am fro the cloud directly (c2) then I must have to use angles. This all came about because a little girl asked me how far away a cloud was. What was it over?

You might be able to work it our (v roughly) from the cloud type. different clouds typically form at different altitudes that might give you a rough height