Download presentation
Presentation is loading. Please wait.
Published byFerdinand Atkinson Modified over 6 years ago
1
Warm-Up: Common Words What are “common words” we use in everyday conversation? Do you have to think about their meaning? What if you didn’t know these words? In today’s lesson you will learn about common words needed to speak the language of geometry
2
What is a definition? Known words used to describe a new word
Undefined terms – not formally defined There are 3 in geometry. Point Line Plane Segments, rays, and angles are defined in terms of these basic figures.
3
Points, Lines, & Planes Objectives Students will be able to:
Define: Point, line, plane, collinear, coplanar, line segment, ray Name collinear and coplanar points Draw lines, line segments, and rays with proper labeling
4
Example what your note page should look like now
Points, Lines, & Planes August 16, 2010 Objectives: Define: Point, line, plane, collinear, coplanar, line segment, ray Name collinear and coplanar points Draw lines, line segments, and rays with proper labeling
5
Point 1. Has no dimension (no length, width, thickness)
2. Usually represented by a dot 3. Named using one capital letter B
6
Points Points do not have actual size. How to Sketch: Using dots
How to label: Use capital letters Never name two points with the same letter (in the same sketch). A B C A
7
Line Extends forever in one dimension (length)
Has an arrowhead on each end representing the fact that it goes on forever Consists of an infinite amount of points Always straight l A B
8
Lesson 1-1 Point, Line, Plane
Lines Lines extend indefinitely and have no thickness or width. How to sketch : using arrows at both ends. How to name: 2 ways (1) small script letter – line n (2) any two points on the line - Never name a line using three points - n A B C Lesson 1-1 Point, Line, Plane
9
Plane Extends forever in 2 dimensions (length & width)
A flat surface consisting of infinitely many points Usually represented by a 4-sided figure A W C B
10
Planes How to sketch: Use a parallelogram (four sided figure)
How to name: 2 ways (1) Capital script letter – Plane M (2) Any 3 non collinear points in the plane - Plane: ABC/ ACB / BAC / BCA / CAB / CBA A M B C Horizontal Plane Vertical Plane Other
11
Different planes in a figure:
B Plane ABCD Plane EFGH Plane BCGF Plane ADHE Plane ABFE Plane CDHG Etc. D C E F H G
12
More Definitions Collinear points – points that lie on the same line
Coplanar points – points that lie on the same plane
13
Practice : Naming Points
Name a point that is collinear with the given points B and E: C and H: D and G: A and C: H and E: G and B:
14
Name a point that is coplanar with the given points
M, N, R: M, N, O: M, T, Q: Q, T, R: T, R, S: Q, S, O:
15
Lesson 1-1 Point, Line, Plane
Coplanar Objects Coplanar objects (points, lines, etc.) are objects that lie on the same plane. The plane does not have to be visible. Are the following points coplanar? A, B, C ? Yes A, B, C, F ? No H, G, F, E ? Yes E, H, C, B ? Yes A, G, F ? Yes C, B, F, H ? No Lesson 1-1 Point, Line, Plane
16
Line Segment (or segment)
A section of a line that has 2 endpoints Named by its endpoints. AB or BA A B
17
Ray Piece of a line with only one endpoint (initial point) and continues forever in the other direction Named by the endpoint and a second point named on the ray. (name MUST begin with the endpoint!) AB A B
19
Opposite Rays 2 rays that share a common initial point and face opposite directions. QP and QS are opposite rays. P Q S
20
A. Name 4 points in the figure.
B. Name the two lines in the figure. C. Name the plane in the figure. D. Name four segments in the figure. E. Name four rays in the figure.
21
Two planes intersect in a line
Two or more geometric intersect if they have one or more points in common. Lines k and l have point A in common, so point A is the intersection Two planes intersect in a line
22
Modeling Activity
23
Activity Questions When the cards are NOT together:
What is the intersection of AB and CD? AB and EF? 2. With the cards together, what is the intersection of CD and EF? 3. What is the intersection of planes M and N? 4. Are CD and EF coplanar? Explain.
24
Assignment General: Worksheet 1.2A Honors: Worksheet 1.2B
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.