Way for a Mouse to Escape a Cat, According to Math

This math puzzle from the YouTuber Numberphile poses a simple question: How can a mouse escape from a cat. If I take the cross product of the vector position of the cat and the position of the mouse, I will get a result in the z-direction (the pool is in the x-y plane). The dash tactic says that there are certain cases where the mouse is close enough to the edge of the pool that it will get there before the cat.

Source: www.wired.com