How to "Mate" two sides?

If I have two shapes, I want to connect them together by two sides, but those two sides are not aligned or at the same angle. How to quickly and easily mate them together (automatically rotate the shape to make those two sides parallel and stick together)? Thanks. For example, I want to connect the pentagon with a triangle. How to perfectly stick one triangle side to the pentagon side? 


Please sign in to leave a comment.