1. BASIC GEOMETRIC CONCEPTS
Chapter 1
BASIC GEOMETRIC CONCEPTS

2. 1. postulate
A statement that is accepted without proof

3. 2. point
A location in space

4. 3. line
A geometric figure made up of infinitely many points; it extends endlessly in two directions

5. 4. Line segment
A part of a line; it has two end points

6. 5. ray
A part of a line; it has one end point

7. 6. plane
A flat surface; it has no thickness; it extends endlessly in all directions

8. 7. Congruent line segments
Line segments that have the same length

9. 8. midpoint
The point that divides a line segment into two congruent parts

10. 9. bisector
A line that intersects a line segment at its midpoint

11. 10. Collinear points
Points on the same line

12. 11. theorem
A statement that can be proved