Section1 2a
- 1. Geometry: The Basics (Section 1-2)
- 2. The Undefined Terms There are three terms that have no definitions, but we can describe them. They are the building blocks that we use to define other terms. 1. Point – a location in space How many dimensions does A• a point have? Point A Zero! Note: A capital letter is used. (It really has no size.)
- 3. The Undefined Terms 2. Line – extends in two directions without ending ⋅ l How many dimensions A B does a line have? AB, or line l One! (length) Note: It can be named using a lower-case letter or by referring to two points on the line. (It has no width.)
- 4. The Undefined Terms 3. Plane – extends in all directions without ending, has no thickness How many dimensions does a plane have? M N Two! Horizontal Vertical (length and Plane M width) Plane N Note: Name using capital letters.
- 5. Some More Vocabulary Space – the set of all points Three dimensions – length, width, and height Collinear Points – points all on the same line Collinear Points Noncollinear Points
- 6. Some More Vocabulary Coplanar Points – points all in one plane • • • • • • • • Coplanar Points Noncoplanar Points
- 7. Some More Vocabulary Intersection – the set of all points common to all figures 2 lines intersect A line & a plane in a point intersect in a point 2 planes intersect or a line in a line
- 8. Now, Some Practice! Classify each statement as true or false 1. P is in M N 2. b is in M X 3. YX contains P b A 4. M contains YX M 5. A is on b Y P 6. A and P are in M 7. N contains P
- 9. More True or False!!! 8. PF ends at P. 9. Point S is on an infinite number of lines. 10. A plane has no thickness. 11. Collinear points are coplanar. 12. Planes have edges. 13. Two planes intersect in a line segment. 14. Two intersecting lines meet in exactly one point. 15. Points have no size. 16. Line XY can be denoted as XY or YX.