I also just tried this on ChatGPT o1. It got the right answer, recognizing it as a degenerate triangle and getting x=1. All I did is upload the image and tell it to give me the length of AD.
Triangle inequality says that if a, b, c are the lengths of a triangle, then
c \leq a + b.
In other words, the length of any one side can't be greater than the combined length of the other two sides. And they're only equal when the triangle collapses to a straight line.
x=1. All I did is upload the image and tell it to give me the length of AD.x=0because triangle inequality. I'll just leave it at that.a,b,care the lengths of a triangle, thenc \leq a + b.x=1. slaps forehead