Undefined terms such (Points,Lines,Planes)
- 2. Prepared by: DAIZY ALARCON AVILA BSED-MATH
- 3. Objectives: describe the undefined terms; name the identified point(s), line(s) and plane(s) in a given figure. represents point, line and plane using concrete and pictorial models.
- 4. Geometry It is a Greek word Geo means “earth” and metron means “measurement”. - define as the measure of the earth Geometry deals with the shapes that we see around us.
- 5. Point • A point is simply a location that has no dimension (width, length, and thickness), it is usually represented by a small dot, and named by a capital letter. A Point A B Point B C Point C
- 6. Line • A line is a set of points and extends in one dimension. It has no thickness or width, is usually represented by a straight line with two arrowheads to indicate that it extends without end in both directions, and is named by two points on the line or a lowercase script letter. A B l Line AB or line l
- 7. Kinds of Lines Line Segment -is a part of the line with two endpoints and all the points between them. Ray -is a part of the line with one endpoint and extends indefinitely in one direction
- 8. Plane • A plane is a flat surface made up of points. It extends in two dimensions, is usually represented by a shape that looks like a tabletop or wall, and is named by a capital script letter or 3 non- collinear points. You must imagine that the plane extends without end, even though the drawing of a plane appears to have edges. Plane ABC or plane M
- 9. A few more basic concepts using these undefined terms . . . Collinear points are points that lie on the same line. Coplanar points are points that lie on the same plane.
- 10. Example 1: Name three points that are collinear Solution: D, E and F lie on the same line, so they are collinear. G D E F H
- 11. Example 2 Name four points that are coplanar. Solution: D, E, F, and G lie on the same plane, so they are coplanar. G D E F H
- 12. Example 3: Name three points that are not collinear. Solution: There are many correct answers. For instance, points H, E, and G do not lie on the same line. G D E F H
- 13. Intersections of Lines & Planes The intersection of two or more lines is a POINT. The intersection of two or more planes is a LINE.
- 14. Example 4: How to sketch a line that intersects a plane in one point Draw a plane and a line. Emphasize the point where they meet. Use dashes to indicate where the line is hidden by the plane.