Video transcript
"hello students welcome to lido q a video
session i am seth your math tutor
and question for today is find the
volume of the right circular cone
with radius 6 centimeter height 7
centimeter
radius 3.5 centimeter height 12
centimeter
height 21 centimeter slant height 28
centimeter
so these three questions we need to
solve here
we'll take one partition and solve one
by one
the very first question here is given
that radius
the radius that is given is 6 centimeter
radius of
right circular cone
that is r and that is equal to 6
centimeter now height is given that is
height of
right circular cone h
is equal to 7 centimeter
what you need to do over here is just
apply the formula for volume of a right
circular cone
so volume of a right circular cone
is equal to 1 by 3 pi
r square h so that is equal to
v that is 1 by 3 into
3.14
into the radius is 6 square
that is radius square into height that
is 7
solving this you will get 264
centimeter cube as your volume of the
right circular cone
now the second thing over here you need
to find is
again the volume of the right circular
cone from the given data of radius
and height so radius here
that is r given that is 3.5 centimeter
and height
h that is 12
centimeter again you apply the same
formula
that is volume of a right circular cone
one by three pi r square
h 1 by 3 into
3.14 into radius square is 3.5
square into 12
square so that is equal to
here 154 centimeter cube
so your volume of a right circular cone
over here
is 154 centimeter cube
now in third question you have been
given height
and slant height for right circular cone
height is 21 centimeter
and your slant height
let us consider it as letter l that is
28 centimeter
the very first thing you need to find
here is the radius of
right circular cone because in the
formula for the volume of the right
circular cone
we have one term containing radius that
is 1 by
3 pi r square into h
so here you need to first of all find
the radius of the right circular cone
so radius of the right circular cone can
be given by
r square plus or you can write directly
h square is equal to l square that means
r square is equal to l square minus
h square
your slant height is 28 centimeters or
28 square
minus h square that is 21
square so your r square comes out to be
49 into
7 so here you can write it like this
that r is equal to
7 root 7
once you found this r
then you have formula for the
volume of the right circular cone
one by three pi r square h
that is 1 by 3 into 3.14 into radius
square that is
7 root 7 square
into 21 square
1 by 3 into one four
into seven if you calculate this then
you can get
an answer like this
around seven five four six seven five
four six
and the unit is centimeter square
so a volume of the right circular cone
for this will be seven five four six
centimeter square
sorry it is a cube because volume is
there so here
q
your final answer for this again i'm
repeating that is
7546 centimeter
cube
so this is our solution for each of
these given questions
if you have any doubt you can post it in
our comment section and subscribe to our
channel for more such interesting
questions
thank you for watching
"