Originally posted by aginis
ok how about this one
you are standing in a large square room 100x100x10 ft
in the center of the room hang down to ropes each 10 ft long. the ropes are 16ft apart. your objective is to tie the two ropes together to form a triangle with the ceiling. your only tool is a large razor sharp machette.
GO!

I like the swinging rope solution, but I think the solution you're looking for is to cut off 6 feet plus enough to tie a couple knots from one rope, tie it to the end of the other rope, and then tie the remaining end back to the original rope. To form the triangle, rather than an arc, you'd probably want to weight the rope sufficiently, either by hanging yourself or the machette on it.