How to determine the touch of objects?

Question

JavaScript

I want to touch objects in Javascript. I understood how to touch a circle, a square. But, and if, for example, an object touches another braid or a ray crosses a square, how to determine where it crossed it?

Answer 1

That is, you stubbornly do not want to study theory ?
UPD:
There is a beam

It is better to open in a separate window. On LMB you can move the point of the beginning of the beam.