Region/Size/Space Figure/Straight Edge/Vertex
REGION A closed curve and all the points inside it.
SIZE Refers to the amount of opening between the side (rays) of the angle.
SPACE FIGURE A figure encloses a part of space.
STRAIGHT EDGE Has no marks on it with which measurements can be made; by tracing along its edge one can construct a line segment.
VERTEX A common endpoint of two rays, two segments, or three or more edges of a space figure. Illustration: