I got help on another website. I was told about the arclength formula and that I was to figure out the angle spanned by the 5400 km arc between Montreal and Paris. I'll try working it out from there.
Yes.
This is the drawing: http://imgur.com/yfNVc
This is what I came up with: http://imgur.com/x61XV (I forgot something, The intersection of the lines is O)
The more I look at it the sillier it seems.
First, I know that θi = θr
From that, I concluded that angle BAO = angle DAO
Thus...
"At what minimal height must be situated the point of reflection of a radio wave emitted in Montreal and received in Paris? The distance which separates both cities is 5 400 km and the radius of the Earth is 6 400 km."
I don't even know where to start, we didn't learn this. I would assume the...