What is the midpoint of a line segment?
The midpoint of a line segment is the point on the line segment that splits the segment into two congruent parts. A segment bisector that intersects the segment at a right angle. A segment bisector is a line (or part of a line) that passes through the midpoint.
Is a Union of convex sets concave?
To show a union of convex sets is not convex, consider two circles that do not intersect. If we choose one point from the interior of one of the circles and one point from the interior of the other circle, then at least one point in the segment between them is not in either circle, which implies that the union is not convex.
What is the length of a segment?
We de?ne the length of a segment |AB| to be kABk = |AB| |OX| . Note that congruent segments have equal lenghts, and that length is additive, meaning that the length of the sum of two segments is the sum of the lengths of the segments.
How do we conclude the discussion of absolute geometry?
We conclude the discussion of absolute geometry by adding two axioms that allow us to establish a one-to-one correspondence between the points of a line and the real numbers that preserves the ordering. R1.
Geometry Basic Definitions