I first saw this problem when I was in High School (Brooklyn Tech HS) in the early 1960's (Yes I'm getting old.)
There is a narrow alley with a ladder leaning against each wall, starting at the opposite corner.
One ladder is 25 ft long, the other is 20 ft long, and they cross 10 ft above the ground.
To see a picture of this problem goto my website:
I can draw it, I could build it, but I can't solve it mathematically.
There should be a way to solve it. Since there is enough information to draw and build it, there should be only one possible solution.