hi
i know this is a bit basic but i couldnt find anything that pinpoints my problem, usually if i want to align shapes side-by-side so that they have no gap between them, or 0px, i do it by cloning the shape and moving it along the direction its going and then zooming in on the gap. this is a 'by-eye', i'm sure theres a more definitive way to do it.

for example, if i am joining two square shapes together, to make a rectangle, how can i make sure the join is seamless and perfect?

thanks?