00:01
Okay, it looks like here we just need some definitions and drawings for each of the following.
00:06
So if you are studying euclidean geometry, which is based on the studies of euclid, then three of the terms listed here are what euclid called undefined terms.
00:23
He just felt like these terms were so obvious, they didn't really need a definition.
00:29
And so those three undefined terms are a point.
00:34
A line and a plane.
00:38
So when we talk about definitions for these terms, keep in mind that technically these are undefined terms, but we can describe them.
00:46
So a point has no dimension, has no dimension, and it's represented by a dot.
00:57
Let's see if i can spell dimension.
00:59
So we represent it by a dot.
01:01
Really it has no dimension, but we represent it by drawing.
01:05
That dot.
01:07
A line has one dimension.
01:09
So it has one dimension.
01:18
It's represented by a line with two arrowheads and because what these arrowheads represent to us is that the line continues or extends without end.
01:31
So it has, i didn't spell one correctly, it has one dimension, it extends without end.
01:38
And we represent it with a line with two arrows.
01:43
And then a plane.
01:44
So a plane has two dimensions.
01:51
It also technically extends without end.
01:56
Extends without end.
02:01
And we typically represent a plane by drawing something like this.
02:07
And what's in here is our plane.
02:12
So those are the three undefined terms.
02:15
Now you've got some other terms, which certainly do have a definition.
02:20
Let me go to a page.
02:22
And one is a line segment.
02:26
So line segment, and we have array, and then we have all polygons having between three and ten sides.
02:39
So let me go ahead and write that down.
02:42
All polygons, three to ten sides.
02:47
All right, so the definition of a line segment.
02:51
We would draw the segment, okay, and then we have end points a and b.
03:05
And then the definition, the line segment a, b, consists of points a and b, and all points and all on a, b.
03:40
Between a and b.
03:47
So we have a line segment and we write it like i wrote it down there with a straight line over it.
03:53
A line segment, a, b.
03:56
It consists of the points a and b and all points on the segment that are between a and b.
04:01
And then we have array.
04:03
We write array...