1. Date: Topic: Points, Lines, and Planes (6.1) A point is the basic building block of geometry. It has not shape of size., only location. You use a dot to picture a point, R A line is a series of points that extends in two opposite directions without end. It appears to have some thickness, but actually has none. P Q m A plane is a set of points that extends without end in all directions along a flat surface. It has no thickness or edges, usually you picture a plane as a four-sided shape. W

2. Space is the set of all possible points. U P, T, and Q are _______________ A coplanar points are points that lie on the same plane. A, B, and C are _______________ A intersection of two geometric figures is the set of all points common to both figures. Collinear points are points that lie on the same line. P Q T P, T, and U are _______________ D A B C A, B, C and D are _______________

3. A line segment is the part of a line consisting of two endpoints and all the points between them. It begins with one point and ends with another. Ray is part of a line consisting of one endpoint and all the points of the line on one side of the endpoint. It begins at one point and extends without end in one direction. Q T G F

4. Postulates are accepted as true without proof. Unique Plane Postulate: Through any three noncollinear points, there is exactly one plane. (Three noncollinear points determine a plane.) Unique line Postulate: Through any two points, there is exactly one line. (Two points determine a line.) P Q A B C Postulate: If two points lie in a plane, then the line joining them lies in that plane. A B C

5. Postulate: The distance between any two points on the line is equal to the absolute value of the difference of their coordinates. Postulate: If two planes intersect, then their intersection is a line. Segment Addition Postulate: If point B is between points A and C, then AB + BC = AC. -3-201234567 PRSQ Find the length of -3-201234567 ACB AB + BC = AC