Friday, October 16, 2009

2.4 Use Postulates and Diagrams

Goal: Use postulates involving points, lines and planes.


Vocabulary

A line is a line perpendicular to a plane if and only if the line intersects the plane in a point and is perpendicular to every line in the plane that intersects it at that point.


Postulate 5 Through any two points there exists exactly one line.


Postulate 6 A line contains at least two points.


Postulate 7 If two lines intersect, then their intersection is exactly one point.


Postulate 8 Through any three noncollinear points there exists exactly on plane.


Postulate 9 A plane contains at least three noncollinear points.


Postulate 10 If two point lie in a plane, then the line containing them lies in the plane.


Postulate 11 If two panes intersect, then their intersections is a line.