Drawing the Nets of Various Shapes Video Lecture - Class 7

this is the figure of a triangular prism
it's a triangular prism because the two
bases are triangles and the other faces
are rectangular if there were two
rectangles as the basis it would have
been called a rectangular prism or a
cuboid now let's try to draw the net of
a triangular prism
let's take its duplicate and dissect it
there are many ways in which we can open
it up along its edges we can start off
by opening the rectangular face on the
right then we can open up the
rectangular face on its left then drop
the two triangles to get this this is
the net of a triangular prism and the
top view will look like this the yellow
and the red rectangular faces are the
faces to the right and the left of the
prism the black one is at the bottom the
green and the blue ones are the
identical parallel faces in the front
and the back remember this is not the
only possibility let's zoom out and see
the different possibilities the prism
may be opened up to look like this we
can see that the position of the green
triangle has changed the prism can be
opened up to look even like this let's
zoom out and see another possibility it
might look like this it all just depends
on how you open it up all these nets are
possibilities for this prism let's take
another example here's a square pyramid
it's called a square pyramid because
it's base is a square and all other
faces are triangles one base and four
triangles if the base was a triangle it
would have been called a triangular
pyramid forget this solid for now I want
you to try drawing the net of this solid
give it a shot
let's try drawing it using pen and paper
to make sure you cover all faces it's a
good idea to name them all
let the square at the bottom be called
be and the four triangular faces be
called t1 t2 t3 and t4 the triangle in
the front t1 the triangle at the right
t2 the triangle behind d3 and a triangle
to the left t4 to draw its net let's
draw its base first we draw a square
like this and name it B and now it's
pretty simple there is a triangle
attached to each side of the base
opening up the four triangles along the
sides of the base will give us this four
triangles attached to each edge of the
square this is the net of a square
pyramid and the top view will look like
this this is the base and four triangles
attached to the sides of the square but
what if the faces of the solid are
curved and not straight how would we
draw the net a cylinder and a cone are
two such examples
what would the net of these two solids
look like assume this is an open
cylinder which means that the two
circular bases do not exist and this is
an open cone with dr. circular base now
take a moment and think about how the
nest would look like
okay so the net of a cylinder is simply
a rectangle yes opening it up like this
gives us a rectangle this is the height
of the cylinder and this is the
circumference of the circles at the top
and the bottom and what about a cone
opening it up like this gives us a
sector of a circle yes the slant height
of the cone will be the radius of the
circle of this sector so we have seen
how we can draw net from the solids that
are given to us but would you be able to
draw the solid given the net is it easy
we see that in the next session
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