Three-Dimensional Figures - Free Educational videos for Students in K-12 | Lumos Learning

Three-Dimensional Figures - Free Educational videos for Students in k-12


Three-Dimensional Figures - By Anywhere Math



Transcript
00:0-1 Welcome anywhere , matt . I'm Jeff Jacobson . And
00:03 today we're gonna talk about three dimensional figures . Go
00:10 , let's get started . Alright , for today's lesson
00:31 , there's gonna be a lot of terms and a
00:33 lot of pictures and drawings to make . So make
00:36 sure you take really , really good notes . Okay
00:39 , so today we're talking about three dimensional figures and
00:42 before we get to any examples , there's quite a
00:44 lot of terms and vocabulary words that we need to
00:47 talk about . So first , if I look at
00:51 all of these , well what are they we call
00:54 them ? Solid and solids are three dimensional figures that
01:00 take up space . You've got a cube , pyramid
01:04 , triangular prism . Uh We got a cylinder ,
01:08 a cone and a sphere . They're all solid .
01:12 Some of these look like they might belong together .
01:15 And some of them don't . Okay . The next
01:19 word , we're going to talk about our poly Hadrian's
01:22 . Well , which ones of these are poly hydrants
01:25 . Holly hydrants are three dimensional figures , right ?
01:30 But all of the faces are polygons . So that
01:34 means if there's anything that looks rounded like a sphere
01:38 , it's not a poly hedren . So this doesn't
01:40 work . Uh cylinder is also not a poly hedren
01:44 comb . Not a poly hedren . Right ? It's
01:47 rounded on this part here . At the base is
01:50 a circle . That doesn't work . But these ones
01:53 left over . Yes . Pyramid is definitely apology .
01:56 Adrian cube for sure , triangular prism . Those are
01:59 all Polly Hadrian's . All of these faces are polygons
02:05 . Okay . Next we're gonna take a look at
02:07 a cube and talk a little bit more about some
02:10 more vocabulary words to describe this cube . First word
02:14 we're going to talk about is face . Well what
02:17 is a face on a on a poly hedren ?
02:20 We're not talking about a face like this . Faces
02:22 like a side of a poly hedren or a three
02:26 D . Figure . So if you look at this
02:28 cube , how many faces does it have ? Well
02:31 we've got the front and the back . That's too
02:34 we've got the left and the right . That's two
02:37 more . So that's four and we've got the top
02:39 and the bottom . So all together this has six
02:42 faces . Next let's talk about this part . Right
02:46 here we call this an edge and edges where two
02:51 faces meet . That's all it is . So we've
02:54 got an edge here where this facing this face meat
02:58 edge right here with this face in this face meat
03:01 . So if we look at this cube , how
03:02 many edges does it have ? Well we've got 1234
03:09 5678 and on the bottom 9 10 11 12 12
03:16 edges in this Cube . Next word we're going to
03:19 talk about is right here that's called the vertex And
03:24 a vertex is where three edges meet . So right
03:29 here this vertex there's an edge . An edge and
03:32 an edge where they meet that's called a vertex .
03:36 Well , how many virtues is that's plural for vertex
03:40 does this cube have ? So let's see , we've
03:42 got one here . 234 And then on the bottom
03:47 56788 vortices . Here's one to shine your own .
04:01 Next . We're going to talk about a couple of
04:03 very common polly hydrants and the first is in prison
04:08 . Okay . A prism is a poly hadron that
04:12 has two identical parallel basis . And we're not talking
04:18 about base like two dimensional . Like when you find
04:21 the area of a parallelogram and its base times height
04:25 . We're talking about uh sides or faces as the
04:29 basis . So for example , this is a prism
04:34 . It is a triangular prism . And the reason
04:36 it's a triangular prism is because the basis are triangles
04:41 . You name the prism after the base . So
04:44 right here there's a triangle . Here's another identical triangle
04:49 and they are both parallel with each other , which
04:53 is why it's called the triangular prism . The way
04:56 I like to think of prisms as think of the
04:59 base as whatever shape is being stretched . Okay ,
05:04 so it's like we've got a triangle here and I
05:07 take that triangle and I stretch it out to make
05:09 a prism . Now one other thing to know about
05:13 prisms is that these faces in between the basis are
05:21 always going to be parallelogram and we call them lateral
05:25 faces . Okay , so these these faces in between
05:30 the bases are lateral faces . So here's a triangular
05:34 prism . Uh Here's another example of a triangular prism
05:39 , right ? It's smaller but same thing you've got
05:42 a triangle and you're stretching it out to make a
05:44 prism . Uh Here you can call this a square
05:48 prism . Here's a square , an identical square that's
05:51 parallel another prism . And notice the lateral faces are
05:55 still parallelogram . They're rectangles but rectangles are parallelogram .
05:59 So that's okay , these are prisms . The next
06:03 Paula , Hedren we're going to talk about is a
06:05 pyramid . Now , I'm sure all of you know
06:07 , pyramids , you know , like the pyramids in
06:09 Egypt and stuff . But let's get technical about it
06:12 . A pyramid unlike a prism only has one base
06:17 . So this base is a square , which means
06:21 we call this a square pyramid if you had a
06:25 pyramid like this ? Well , the base here is
06:31 a triangle . So this is not a square pyramid
06:34 . It's a triangular pyramid . So , you name
06:38 the pyramid after whatever shape the basis . Okay ,
06:43 now , if we look at these pyramids , the
06:45 lateral faces , these here and here , they are
06:50 not parallel , ingram's like they are in prisons instead
06:53 . They're always gonna be triangles . Okay , so
06:57 here are pyramids . Ok , I was able to
07:00 draw a rectangular prism . Now it's a rectangular prism
07:04 , which means the basis need to be rectangles .
07:08 So to draw you need two identical rectangles . So
07:12 I'm gonna start with the first one . Next step
07:14 , you just go up and over a little bit
07:17 to draw your second and try to make it identical
07:20 to this at this point . All you need to
07:22 do is connect the corresponding angles . So top left
07:27 , I connect with top left , like that ,
07:30 bottom left with bottom left , top right with top
07:34 right and bottom right with bottom right . So now
07:40 you can start to see it looks three D .
07:42 Like a rectangular prism . Last thing is you have
07:45 to make the the lines that you can't see .
07:48 We call those the hidden lines , you make those
07:51 dashed . So this is where you need a pencil
07:53 . So I'm just gonna erase that's going to be
07:57 a hidden line because I wouldn't be able to see
07:59 it looking at the prison from the front that would
08:03 also be hidden . And so would that one .
08:09 So that is the rectangular prism . Let's try one
08:13 more . Okay , part be dry triangular pyramid ,
08:18 triangular pyramid means that base is going to be a
08:21 triangle . So I'm going to start with that and
08:23 then remember all of the , all of the sides
08:25 come up to a point come up to a vertex
08:28 . So you put a point up here and just
08:30 simply connect each of those uh vertex is up to
08:37 that point like that . And then you gotta make
08:40 your hidden line . So I'm gonna make it as
08:42 this this face here is going to be the front
08:44 . So these are gonna be all hidden . Okay
08:54 ? And that is your triangular pyramid . Now real
08:56 quick . If you wanted to do a square pyramid
09:00 , you gotta be careful because if you do the
09:03 same technique and draw a square point and then up
09:07 here you're gonna look at that and say that looks
09:12 really weird . Right ? Well the trick is to
09:15 not draw a square , make it look more like
09:18 a parallelogram kind of slanted . So if you draw
09:23 it like that then you put your point up there
09:26 if you want to go over a little bit so
09:28 I can see that that line and that line are
09:30 different , connect those , connect those and then make
09:36 your hidden lines . Hopefully that looks a little better
09:41 . Right ? That definitely looks better than the other
09:42 one . Let's try one more example , our here's
09:45 our last example , draw the front side and top
09:48 views of the solid . So we're gonna do this
09:51 triangular prism . So the front view is if it's
09:55 sitting like this , what does it look like coming
09:57 from the front ? Well when we're drawing these views
10:00 you can't see three D . So when we draw
10:04 it it's just gonna be a two D . Shape
10:06 . So from the front all you see is you
10:08 see this bottom line and that top and then it
10:12 just looks like a straight line coming down . We
10:14 can't draw angle like we know it is it's just
10:17 coming straight down . So a front view , make
10:21 sure you label each of these Front view would look
10:24 just like a thank you . There's my front view
10:28 next the side view again . Well that would be
10:31 coming from the side . Well we know the side
10:35 of this triangular prism is a triangle here , that's
10:38 one of those bases . So side view is just
10:41 a little triangle . And keep in mind these heights
10:47 here should be the same , right ? Okay .
10:50 Uh so keep that in mind when you're making your
10:52 drawing , it wouldn't make sense to draw a huge
10:54 triangle if that was my front view . And finally
10:57 the top . What does it look like when you
10:59 look at this figure from the very top straight down
11:03 ? So if I turn it and you look well
11:06 it's gonna look like a rectangle with this line right
11:10 in the middle , okay , for that top edge
11:13 . So that's your top you so you're gonna have
11:17 another rectangle but that's going to have that line going
11:22 right through the middle . Here's some more to try
11:25 on your own as always . Thank you so much
11:34 for watching . And if you like this video ,
11:35 please subscribe .
Summarizer

DESCRIPTION:

OVERVIEW:

Three-Dimensional Figures is a free educational video by Anywhere Math.

This page not only allows students and teachers view Three-Dimensional Figures videos but also find engaging Sample Questions, Apps, Pins, Worksheets, Books related to the following topics.


GRADES:


STANDARDS:

Are you the Publisher?

EdSearch WebSearch