Difficulties: How to determine the point M? Because the side lengths of the left right-angled triangle are 3, 4 and 5 respectively, only when the right-angled sides are the same can an angle of 45 be formed, so we will move a square on the X axis-see the L 1 line in the figure, and its included angle with the y=x line is α (at this time, the side lengths of the triangle formed by the L 1 line and the coordinate axis are 3 and 3 respectively).

Third, as long as CP and CQ are equal, then point D can be found to form a diamond. When the time is determined to be 2.5 seconds, CP=CQ=2.5 unit lengths, and then the coordinates of point D can be obtained by using the properties of the midpoint midline.

The second problem is that the calculation process is not given, and the landlord has to do everything himself.

It is not easy to answer questions, I hope I can help the landlord.