Notes from 9/5

Notes from 9/5
September 5, 2012
• Seats, Syllabus, Textbook
• Sec 1.1: The Building Blocks of Geometry: Points, Lines, Planes etc.
Objectives:
• We will explore basic geometry terms and notations.
• Investigate postulates about points, lines, and planes.
Notes from 9/5
Point A point describes a location, but has no size.
Ex:
Notation
Written with only capital letters
Diagram
Notes from 9/5
Line or Straight line: • Infinite number of points • Extends infinitely far in both directions (Infinite length)
• No thickness
• Ex:
Notation
Two points on the line with double
arrow bar above or lowercase letter
Diagram
Notes from 9/5
Plane:
A plane is a flat surface that extends infinitely in all directions.
Ex:
Notation
1) Three non­collinear points OR
2) Cursive capital letter
Diagram
Notes from 9/5
Space: Space is the set of all points.
Collinear Points: Points that lie on the same line
Noncollinear Points: points that do not lie on the same line.
Notes from 9/5
Coplanar: points that lie on the same plane
Noncoplanar: points that do not lie on the same plane
Notes from 9/5
Segment:
A part of a line that begins at one point and ends at another
­ Essentially two endpoints and the line in between
Ex:
Notation
Two points on segment with a bar over it.
Diagram
Segment vs. Distance (Segment Measure)
Notes from 9/5
Ray:
A ray is a part of a line that starts at one point (endpoint) and extends infinitely in one direction.
Ex: Notation
Two points on the ray
Order matters!!! Diagram