The length of oA is (1-m), and the length of OB is 3.

OA & ltOB, with (1-m) 3 < 3.

Because 1-m > 1, m < 0.

But there is something wrong with your answer. The graphics problem depends on the conditions given in the title, not the conditions obtained from the picture. If so, in the geometric proof problem, as long as you see that the two line segments in the diagram are equal, you can draw a conclusion directly, which is not possible.

Therefore, the condition of OA < OB cannot be used.