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Math Basics: Line, Segments, and Rays 20 Views
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Description:
If you came here looking for manta rays, you're going to be sorely disappointed. This is a math video. About math rays, lines, and segments. Seriously, it's right in title.
Transcript
- 00:04
Lines, Segments, and Rays, a la Shmoop. [Space invaders in the background]
- 00:07
This is Astrid. She’s first in line at a midnight video game release. [Astrid's parents look annoyed]
- 00:12
It’s currently 9 PM. [Astrid looks embarrassed]
- 00:14
With such a long time to wait, Astrid is bored out of her mind, and wonders if there’s
- 00:18
a way she can make her situation more interesting… [Astrid looking thoughtful]
Full Transcript
- 00:21
For once in her life, she decides to relate her circumstances to a mathematical concept. [A lightbulb appears over her head]
- 00:27
Astrid is a stationary point at one end of the line, so let’s call her point “A.” [Astrid stood at point A]
- 00:34
Her best friend Basil just got in line at the other end; he can be point “B.” [The line fills up with people]
- 00:40
More and more people keep appearing behind Basil, because the game is so darn popular… [A long queue of people]
- 00:44
in fact, the line is growing… infinitely. [People keep joining to back of the line]
- 00:48
If Astrid never moved from the front of the line, we would say she’s standing in a ray.
- 00:54
It has one endpoint, “A,” and extends infinitely in the direction of point “B.” [An arrow demonstrates the ray]
- 00:59
So we would call it ray “AB.” Now imagine someone cuts in front of Astrid
- 01:05
while she’s distracted. [A guy jumps to the front of the line]
- 01:06
And while she was busy arguing with that person, another person cut in front of them. And so on. [People keep jumping to the front]
- 01:12
If the back of the line kept growing indefinitely and the front of the line was also growing
- 01:16
indefinitely as more and more people cut, we would call this line “AB.”
- 01:20
That’s right; a true line, in mathematical terms, extends infinitely in both directions. [The line is shown with a double ended arrow]
- 01:26
So in reality, Astrid and Basil are currently waiting in a line segment – specifically,
- 01:31
a line segment with endpoints “A” and “B.”
- 01:35
So it would be technically inaccurate to say they’re waiting in… line. [Astrid looked annoyed and jumping around]
- 01:38
Well, that killed about two minutes.
- 01:40
Only another two hours and 58 minutes to go until she can get her hands on Math Blasters 4: Revenge. [Astrid with her thumbs up]