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.
0. Definition: The measure of an arc of a circle is equal to the measure of the central angle that intercepts the arc. 1. Inscribed angle theorem. The measure of an inscribed angle is equal to one-half the measure of its intercepted arc.. The measure of an angle formed by a tangent and chord is equal to one-half the measure of its intercepted arc. A useful pair of auxiliary lines is to contruct an isosceles triangle with one side parallel to the tangent line.