Warm-up 1. 5x + 4(x – 1) = (x+2) = 3(x – 6) x – 4(x+1) = 2x + 20

Points, Lines and Planes Points, Lines and Planes Section 1.2 SOL:

Points An undefined term in geometry. They have no size How do you represent a point? By using a dot How do you label a Point? With a capital letter Never use the same letter on two different points. What are some examples of points? Stars, Corner of the room A B BX C

Lines Undefined term in geometry. They are made up of points and have no thickness or width. They Extend indefinitely There are 2 Ways to label lines: 1. Using small script letter – line t 2. Using any two points on the line – Never name using three letters - tX Y Z X

Examples of lines: Phone lines strung between poles, spider webs, sun beams. Collinear Points: Points that lie on the same line. Non-collinear Points: Points that do not fall on the same line. A B B A

Planes Undefined term in geometry Are thought of as flat surfaces that extend indefinitely in all directions and have no thickness. There are two ways to label planes: 1. Using a capital script letter – S 2. Using any three non-collinear points – XYZ, XZY, YXZ, YZX, ZXY, ZYX S X Z Y

Coplanar: Points that lie on the same plane. Non-coplanar: Points that do not lie on the same plane.

Example: Use the figure to name each of the following. 1. Give two other names for. 2. Give two other names for Plane R. 3. Name 3 collinear points. 4. Name 4 points that are coplanar. 5. Name a point that is not coplanar with points Q,S,and T. V R Q S P T m n

Example: Draw and label a figure for each relationship. R A P E B D C

Space Is a boundless three dimensional set of all points. Space can contain lines and planes.

1. How many Planes are there? 2. Name three points that are collinear. 3. Are points A, B, C, & D coplanar? Explain. 4. At what point do and intersect?

1. How any planes are there? 2. Name three collinear points. 3. Are points G, A, B, & F coplanar? Explain 4. At what point do and intersect?

Activity 1. Each student gets two cards 2. Label one Q and one R. 3. Hold the two card together and place a slit halfway through both cards. 4. Hold cards so that the slits matchup and slide them together. (Tape cards together) 5. Where the cards meet models a line. Draw the line and label two points C and D on the line.

Activity Cont. 1. Draw point F on your model so that it lies in Q but not R. Can F lie on line DC? 2. Draw point G so that is lies in R but not Q. Can G lie on line DC? 3. If point H lies in both Q and R where would it lie? Draw it on your model. 4. Draw a sketch of your model on your paper. Label each thing appropriately.

Assignments Classwork: WB PG , 20, 21, 23, 27 Homework - Handouts