The meaning of Erastus is Lovely and  Beloved. Its origin is Variant of the Greek name Erastos. Erastus is a form of Erastos and is generally pronounced like eh RAS tus. This name is mostly being used as a boys name. Last year it ranked 4,160th in the U.S. Social Security Administration list of most popular baby boy names.
Which undefined term is needed to define an angle? Plane Point Ray Line. Undefined, you need a line to define an angle (if you're looking for undefined terms). This is because, if you think about it, a ray is part of a line.
1. (Mathematics) the space between two straight lines that diverge from a common point or between two planes that extend from a common line. 2. (Mathematics) the shape formed by two such lines or planes. 3. (Mathematics) the extent to which one such line or plane diverges from another, measured in degrees or radians. 4. an angular projection or recess; corner. 5. standpoint; point of view: look at the question from another angle; the angle of a newspaper article.