1. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles Warm Up Warm Up California Standards California Standards Lesson Presentation Lesson PresentationPreview

2. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles Warm Up Solve. 1. x + 30 = 90 2. 103 + x = 180 3. 32 + x = 180 4. 90 = 61 + x 5. x + 20 = 90 x = 60 x = 77 x = 148 x = 29 x = 70

3. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles Preparation for MG3.1 Identify and construct basic elements of geometric figures (e.g., altitudes, midpoints, diagonals, angle bisectors, and perpendicular bisectors; central angles, radii, diameters, and chords of circles) by using a compass and straightedge. California Standards

4. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles Points, lines, and planes are the building blocks of geometry. Segments, rays, and angles are defined in terms of these basic figures.

5. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles A point names a location. A Point A

6. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles A line is perfectly straight and extends forever in both directions. line l, or BC B C l

7. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles A plane is a perfectly flat surface that extends forever in all directions. plane P, or plane DEF D E F P

8. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles G H A segment, or line segment, is the part of a line between two points. GH

9. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles K J A ray is a part of a line that starts at one point and extends forever in one direction. KJ

10. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles Additional Example 1: Naming Lines, Planes, Segments, and Rays A. a line Any 2 points on a line can be used. KL or JK Use the diagram to name each figure. Possible answers:

11. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles Additional Example 1: Naming Lines, Planes, Segments, and Rays B. a plane Use the diagram to name each figure. Possible answers: Plane or plane JKL Any 3 points in the plane that form a triangle can name a plane.

12. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles Additional Example 1: Naming Lines, Planes, Segments, and Rays C. four segments Use the diagram to name each figure. Possible answers: JK, KL, LM, JM D. four rays KJ, KL, JK, LK Possible answers:Write the endpoint first. Write the two points in any order.

13. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles When naming a ray always write the endpoint first. Caution!

14. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles Check It Out! Example 1 A. four segments Use the diagram to name each figure. Possible answers: AB, BC, CD, AD B. four rays CB, CD, DA, DC Possible answers: A B C D Write the endpoint first. Write the two points in any order.

15. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles Check It Out! Example 1 C. a line Any 2 points on a line can be used. AB or DC Use the diagram to name each figure. Possible answers: A B C D

16. Holt CA Course 1 8-1 Points, Lines, Planes, and Angles Check It Out! Example 1 Use the diagram to name each figure. Possible answers: A B C D D. a plane Plane R or plane ABC Any 3 points in the plane that form a triangle can name a plane.