Then start from A to B. At this time, the coordinates of B are: 350* (root number 2)/2- 100, 350/2+200* (root number 2)/2.
From B to C, the coordinates of C are:-100,200 * (root number 2)/2.
In other words, Xiao Ming is 30 degrees 200 meters west of his home.
In other words, the first walk and the third walk cancelled out, which means he only walked for the second time.