The world of page layout software and the world of scalable vector graphics were once dominated by clearly distinct and separate software programs. As page layout software matured, SVG elements were added to those programs, to the point that many simple illustrations can be produced directly within the page layout program. In the case of Adobe, this is reflected in the parallel development of InDesign and Illustrator. Along with the ability to work with vector graphics in InDesign came the need to include the most commonly used tools with those graphics in InDesign. The Scissors tool is one such tool.
Any open path drawn with the drawing tools in InDesign can be split with the Scissors tool. Here's how:
You can also split shapes using the Scissors tool:
To remove a piece from a shape using straight lines: