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Warm-up. 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.
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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 B A B X 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 - t X 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 A B
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 Y X Z S
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. n Q 1. Give two other names for . • Give two other names for Plane R. • Name 3 collinear points. • Name 4 points that are coplanar. • Name a point that is not coplanar with points Q,S,and T. V m T P S R
Example: Draw and label a figure for each relationship. D B C P E A R
Space Is a boundless three dimensional set of all points. Space can contain lines and planes.
How many Planes are there? • Name three points that are collinear. • Are points A, B, C, & D coplanar? Explain. • At what point do and intersect?
How any planes are there? • Name three collinear points. • Are points G, A, B, & F coplanar? Explain • At what point do and intersect?
Activity • Each student gets two cards • Label one Q and one R. • Hold the two card together and place a slit halfway through both cards. • Hold cards so that the slits matchup and slide them together. (Tape cards together) • Where the cards meet models a line. Draw the line and label two points C and D on the line.
Activity Cont. • Draw point F on your model so that it lies in Q but not R. Can F lie on line DC? • Draw point G so that is lies in R but not Q. Can G lie on line DC? • If point H lies in both Q and R where would it lie? Draw it on your model. • Draw a sketch of your model on your paper. Label each thing appropriately.