Explore various positions for the vertices of the triangle and the points L, M, and N to verify the following result: If three proper Cevian lines are concurrent, then d= 1. Find examples of concurrent Cevian lines in which all three of the points L, M, and N lie on the triangle triangle ABC and other examples in which at least one of the three points is not on triangle ABC. Verify that d=1 in all cases in which the proper Cevians are concurrent.
When the three lines are concurrent, d=1. I could not find an example where at least one of the three points was not on triangle ABC and the value of d was 1.