1. DO NOW Take a ruler from the bookshelf. Have your syllabus contract out and ready to turn in. Take out your notebook for this class. In your notebook, describe the two types of symmetry and draw an example of each.

2. BUILDING BLOCKS OF GEOMETRY

3. TODAY’S OBJECTIVES Learn the terminology and notation of points, segments, lines, rays, planes, angles, and collinear and coplanar points. Learn the idea of congruence of line segments Learn how to mark congruence of segments on diagrams Begin keeping a notebook of definitions Develop Problem Solving Skills

4. UNDEFINED TERMS Point Line Plane The three most basic building blocks of geometry.

5. POINT Has no size. Only has location Represented with a dot Named by a capital letter

6. LINE Straight continuous arrangement of infinitely many points. Has infinite length but no thickness Extends forever in two directions Named by the letter names of any two points on the line and the line symbol.

7. PLANE Has length and width, but no thickness. Flat surface that extends infinitely along its length and width. Represented with a 4-sided figure, like paper. Named with a script capital letter. P

8. ANCIENT “DEFINITIONS” “A point is that which has no part. A line is breadthless length.” –Greeks “The line is divided into parts, and that part which has no remaining part is a point.” –Chinese

9. IMPOSSIBLE TO DEFINE We would have to use the terms point, line, and plane to define them. So we accept them as undefined and use them to define everything else in Geometry.

10. COLLINEAR On the same line.

11. COPLANAR On the same plane

12. RAY Part of a line Has an endpoint but extends forever in one direction.

13. ANGLE Made up of two rays who share an endpoint.

14. LINE SEGMENT Consists of two endpoints of the segment and all the points between them that are collinear with the two points.

15. CONGRUENT Two segments are congruent if they have equal measures or lengths.

16. PRACTICE

19. TODAY’S OBJECTIVES Learn the terminology and notation of points, segments, lines, rays, planes, angles, and collinear and coplanar points. Learn the idea of congruence of line segments Learn how to mark congruence of segments on diagrams Begin keeping a notebook of definitions Develop Problem Solving Skills

20. EXIT SLIP 1.Draw and mark a figure in which M is the midpoint of ST, SP=PT and T is the midpoint of PQ. 2.Explain your reasoning. 3.Draw an example of collinear points. 4.Define coplanar.