Trimming and Extending
This section covers all the commands used for trimming objects with respect to other objects. The edited object is either trimmed at the trimming object, or extended to meet the trimming object.
NOTE: In 2D Mode, the Trim commands ignore the 3D aspects of any existing lines, and treat them as flat projections onto the XY plane. This means you can trim lines that would never meet in 3D space against each other’s Front-View projections in 2D space. This is a powerful feature, but you must pay careful attention to what you are doing.