Difference between revisions of "Points, Lines, Segments, Angles etc."
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[[Image:Line-ray-segment.png|center|200px]] | [[Image:Line-ray-segment.png|center|200px]] | ||
− | In the picture above we see the difference between a line, a ray and a segment. The line is the figure at the top. As we can see it goes on for ever. The figure in the middle is a ray. It starts at a point and then moves off to the top-right. The line segment is all the | + | In the picture above we see the difference between a line, a ray and a segment. The line is the figure at the top. As we can see it goes on for ever. The figure in the middle is a ray. It starts at a point and then moves off to the top-right. The line segment is all the way at the bottom. |
+ | |||
+ | We will be using line segments a lot in later sections. We will label segments by recording the endpoints. For example: | ||
+ | [[Image:Triangle-segments.png|center|200px]] | ||
+ | In this diagram we see several line segments: | ||
+ | * Sement AP is the line segment connecting A and P. Note that we can also call this segment PA. | ||
+ | * Segment AB (or BA if you like) runs vertically. | ||
+ | * Segment BP is the third segment shown. | ||
+ | |||
+ | AM, MB and MP are also segments. There is also a line in this picture. It is labeled r. | ||
==Resources== | ==Resources== | ||
Ouside source: [[http://www.mathleague.com/help/geometry/basicterms.htm| Math League: Basic Terms]] Click on the link and look at the examples. | Ouside source: [[http://www.mathleague.com/help/geometry/basicterms.htm| Math League: Basic Terms]] Click on the link and look at the examples. |
Revision as of 15:09, 4 January 2009
Points and Lines
A point is a specific location in space. A point is drawn as a dot. Often we label a point with some letter. We would say "Point A" for instance.
Above you see three points labeled A, B and C.
Lines are something you have seen in Algebra. Straight lines go on infinitely far in both directions. Closely related to the line are rays and line segments.
A ray is what we can think of as "half a line". A ray starts at a given point and then goes of to infinity in one direction.
A line segment is just a small part of a line. It starts at one point and ends at another.
In the picture above we see the difference between a line, a ray and a segment. The line is the figure at the top. As we can see it goes on for ever. The figure in the middle is a ray. It starts at a point and then moves off to the top-right. The line segment is all the way at the bottom.
We will be using line segments a lot in later sections. We will label segments by recording the endpoints. For example:
In this diagram we see several line segments:
- Sement AP is the line segment connecting A and P. Note that we can also call this segment PA.
- Segment AB (or BA if you like) runs vertically.
- Segment BP is the third segment shown.
AM, MB and MP are also segments. There is also a line in this picture. It is labeled r.
Resources
Ouside source: [Math League: Basic Terms] Click on the link and look at the examples.