1
a) An angle is the figure formed by two rays that have a common endpoint
The word "angle" is defined
The word "rays" is undefined
b) A line segment consists of two points and all the points between them
The word "line segment" is defined
The word "points" is undefined
c) A triangle is the union of the three segments that intersect at their endpoints
The word "triangle" is defined
The word "segments" is not defined
