1-3 Points, Lines, and Planes

1. 1-3 Points, Lines, and Planes

2. Ex. 1 Identifying Collinear Pts • Point: • Small dot that does not have size and describes a location • Space: • Set of all points • Line: • Series of points that extend in opposite directions without end • Collinear pts: • Points that lie on same line • Are E, F, and C collinear? What line? • Yes, m • Are E, F, and D? • No

3. Ex. 2 Naming a Plane • Plane: • flat surface that has no thickness • Coplanar: • points and lines in same plane • Name using single capital letter or using threenoncollinearpoints or 4 corners of a plane P P Plane P Plane ABC

4. Ex. 2 cont. • Name plane representing front of cube • Always use word plane to name • plane A, plane ABF, plane EFA • Name right side plane • plane BFGC, plane BCG, plane FCB H G E C B A

5. Ex. 3 Finding Intersections • Use postulates • Postulate or axiom: • Accepted statement of fact • What is the intersection of plane HGFE and plane BCGF? • line GF or • What two planes make line BF? • plane ABF and plane CBF GF H G E C B A