In this work, we developed a software tool for the simplified, automated definition and viewing of loci in the plane, an essential task in the design, engineering and architectural fields. The process was started by identifying the most salient geometric loci in the engineering domain (i.e., tangents). A geometric approach was followed to deal with curves from the relative positions of two circles or a circle and a point. The algorithms used can be easily implemented in commercially available CAD software, which testifies to the usefulness and timeliness of the proposed tool. The tool successfully solved all target cases and was implemented as a function with the commercial software Adobe Authorware v.7.0.2