MATH 1730 Study Guide - An Angle, Radian
Document Summary
Ray: a portion of a line, beginning at a point called the endpointand extending infinitely far in a direction ray endpoint. Angle: an angle consists of two rays sharing a common endpoint. This shared endpoint is called the angle"s vertex. The measure of an angle describes the amount of "openness" of the angle"s rays. Is the "openness of an angle" a quantity? (is the "openness of an angle" a measurable attribute?) An angle consists of two rays that share a common endpoint. We measure an angle by drawing a circle centered at the angle"s vertex, then determining the portion of the circle"s circumference cut off (or subtended) by the angle"s rays. A degreeis an arc length representing 1/360th of the circumference of a given circle. Angles formed by rotating the terminal side counter-clockwise have positive measures, while angles formed by rotating the terminal side clockwise have negative measures.
