1. Suzanne Chludzinski schludzinski@hamden.org ILS501-01 The Basic Elements of Geometry schludzinski@hamden.org

2. Building Blocks of Geometry Everything in Geometry is made of the following three basic elements. 1.Point 2.Line 3.Plane

3. Point Has no size Only has location Represented with a dot Named with a capital letter A Point A

4. Line Straight continuous arrangement of infinitely many points Extends forever in two directions Represented by a line with arrows on each end Named by giving any two points on the line or a lower case letter. j Line j A B Line AB

5. Plane Has length and width but no thickness Similar to a flat surface that extends forever along its width and length Represented with a four sided figure and a capital letter in the lower left corner. Named with a capital letter. P Plane P

6. Types of Lines Intersecting: lines that meet in one point. –Perpendicular lines Non-intersecting: lines that never meet –Parallel –Skew

7. Perpendicular Lines Definition: Lines that intersect at a 90 degree angle. 90 degrees

8. Examples of Perpendicular Lines Street Intersections Crosswalks

9. Parallel Lines Definition: Lines that are in the same plane that never intersect.

10. Examples of Parallel Lines Railroad Tracks Yellow Street Lines

11. Skew Lines Definition: Lines that are in different planes and never intersect