Faces, Edges and Vertices of Various Shapes Video Lecture - Class 8

today's video is entitled faces edges
and vertices to begin let's take a look
at some popular geometric shapes and the
terms that go along with them our first
one is a rectangular pyramid rectangular
pyramid has that rectangular shaped base
next we have a cylinder that one's
pretty easy the red cylinder over here
we have the blue sphere we have a
rectangular prism in the center here we
have a cone in the top left hand corner
sorry about that apologize and we have a
cube in the top Center next let's take a
look at some terms you'll need to know
words you'll need to know
the first one is edge and edge is the
place where two faces me so this figure
here you can see has several different
edges face a face is a flat surface of a
solid figure or polyhedron and finally
vertex is a point where two or more
edges meet and if it's more than one
vertex we refer to them as vertices
moving right along
let's take a look at our first shape our
first shape here is a cube now let's
figure out how many faces edges and
vertices a cube has well four faces we
have the front the back the left the
right the top the bottom and when you
count all those up you'll end up with
six faces and then you can do the same
thing for the edges 1 2 3 4 5 6 7 8 9 10
11 12 so we have 12 edges all together
again I apologize about that 12 edges
and finally the vertices or the points
of 1 2 3 4 5 6 7 8
we have eight vertices now it's your
turn
pause the video identify the shape faces
edges and vertices and come back when
you're ready this shape is no surprise
it's a cylinder it has two faces excuse
me three faces atop a bottom and a
curved face it has two edges one at the
top here and one at the bottom and
vertices 0 there are no points in which
the edges meet our next shape pause the
video come back and see how you did this
shape is a rectangular prism it has six
faces twelve edges and eight vertices
you're going to see this pattern repeat
itself over and over next we have this
shape pause the video come back when
you're ready so identifying this shape
was pretty easy it's a sphere but when
you come to the faces it gets a little
bit trickier it has zero faces zero
edges and zero vertices although from
time to time you'll hear people argue
that it in fact has one big curved face
but for our purposes we'll count it as
having zero faces next pause the video
come back when you're ready alright so
here we go again we have a rectangular
prism and as I said before these numbers
tend to repeat on several geometric
shapes we have 6 12 and 8 for the
rectangular prism
moving right along pause the video come
back to see how you did the name of this
shape is a rectangular pyramid and again
as I stated in the beginning of the
video it's a rectangular pyramid because
the base is made up of a either square
or a rectangle it has five faces eight
edges and five vertices
next we have a very popular shape pause
the video and come back when you're
ready
this shape makes us think about ice
cream it's a cone it has two faces one
curved face one edge where the curved
face meets the flat face and vertices a
little bit trickier we have one or zero
so the reason for 1 or 0 is that some
people don't want to call this a vertice
or vertex because it's only comprised of
one edge or one face but I like to call
at least one vertex because it does make
that nice point there so 1 or 0 again
it's going to really depend on what
information you're looking at have a new
shape here pause the video come back
when you're ready all right this one's a
little bit different it's a triangular
prism excuse me a trying a pyramid and
it's a triangular pyramid because the
base is in the shape of a triangle
and it has 4 faces 6 edges and 4
vertices pause the video come back when
you're ready
this guy here it's a triangular prism
and again this figure has 5 faces 9
edges and 6 vertices moving right along
onto a bonus well I don't know about you
but I definitely notice the relationship
between the edges faces and sides of
many of these different figures in this
lesson I've decided to include a bonus
your bonus is to identify the
relationship between the faces edges and
vertices in a regular polyhedron or a
geometric figure without curves then
write a rule or formula that can be used
for determining the faces edges and
vertices of a geometric figure and if
you need help you can use the hint below
hint if you need help
the formula is named after Lienhard
Euler good luck