To cut your crown molding to fit the corner, you must know the angle formed by the two walls. The easiest way to do this is by using a 360-degree adjustable protractor such as the Original True ...

Cove molding, for example, has a ... If your ceilings are ... the molding has to be cut at a 45-degree angle so the pieces seamlessly connect—like this! or this!—but where the molding butts up ...