Answer
.25
Work Step by Step
While one can solve this problem using Math, we can also solve this problem qualitatively. In order for a shape to be a triangle, two of the sides formed must add up to be greater than the length of the longest side. Since there are infinite points on a line, the odds are effectively 100 percent that the first point chosen will not be in the middle of the rod. This point effectively breaks the rod into two pieces of different sizes. If the point chosen happens to be on the shorter piece, the triangle cannot be formed, and if the point chosen is on the longer piece in a location that makes it so that the two shortest sides formed are less than or equal to the length of the longest side, the triangle will not be formed. Considering this, we see that there are four possibilities, and only one allows a triangle to be formed. Thus, it follows that the probability is $1/4=.25$.
