gao!!!

gao!!!

Yes, instinctively, running vertically is the best way. You show us how to confirm. Though I don't know how you do "qiudao", it make sense for me. I'm going to review "qiudao". Thanks.

I also have difficulty in solving the equations:
v=cos(theta) and sin(theta)/v=Pi+theta. Could you explain it? or could you help me find some basic knowledge to solve this kind of problems?