Is this geometry statement incomplete?

If a line intersecting two other lines makes the alternate angles equal to one another, then the lines will be parallel.

Now if you go to this neat website

http://www.mathsisfun.com/geometry/alternate-interior-angles.html

You see that the two "parallel" lines seem to converge eventually (it's off page). I am not sure if this is just "bad drawing" (doubt this) or the statement needs working.

What do they mean by 'alternate angle'? Exteror or Interior?

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Alternate here basically means on one side of the line then the other---alternating sides of the line. Hopefully that helps. –  Raymond Cheng Oct 18 '12 at 1:45
Do you have a picture? –  sidht Oct 18 '12 at 2:28
They look perfectly parallel to me. Try measuring the distance between them at different points along their length. It might be an optical illusion. –  Alan Gee Oct 18 '12 at 7:59