a right triangle with sides 3 cm,4cm, 5cm is roated about the side 3 cm to form a cone find the volume of cone so formed explain in detail
2007-02-04 04:21:44 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
When we rotate a right-angled triangle about the base, a cone is formed whose base radius(r)=base of right angled triangle, height(h)=height of right angled triangle and slant height(l)=hypotenuse of the right angled triangle. Hereby, r=3cm, h=4cm and l=5cm. Volume of the cone so formed=(1/3)*pi*(r^2)*h
=(1/3)*(3.141)*(9)*4 cubic cm
=37.31508 cubic cm
2007-02-04 04:42:36 · answer #1 · answered by Anonymous · 0⤊ 0⤋
if it's roated about the side 3 cm, it means that this side is the height of the cone... the side 4 cm is the radius of the circle which forms the base...
you have to use the following formula in order to find the volume:
V = (pi)r² x h / 3 where 'r' is the radius and 'h' the height
V = (pi)4² x 3 / 3
V = 16 pi cm³
2007-02-04 04:46:54 · answer #2 · answered by Anonymous · 0⤊ 0⤋
volume of cone = 1/3 pi r sq h
so
=1/3*22/7*4sq*3, here radius = 4 & height = 3,
therefore answer =50.275184cm cube
2007-02-06 18:55:51 · answer #3 · answered by Anonymous · 0⤊ 0⤋
The volume of a cone is 1/3(Area of Base)(height) = 1/3(¶r2)(height).
volume of a cone = pi*r^2h/3
where your cone is r=3cm and h = 4cm
2007-02-04 04:32:26 · answer #4 · answered by ? 4 · 0⤊ 0⤋
The question might be probably wrong, as if we rotate along side
3 cm, we dont get 2 cones.
If it is rotated along its hypotenuse then here is the answer:-
Ok, first of all refer to page of:-
NCERT MATHEMATICS Pg 242 example 11 for understanding the diagram.
Now as you can see your diagram in the book
^ABC is right angled at B.
In ^CBA and ^BOA,
angle c = angle c (common)
Angle B = Angle O (each 90 degree)
^ ~ by AA rule
CB/BO = BA/OA = CA/BA
BA/OA = CA/BA
BY CROSS MULTIPLYING WE GET,
BA2=CA x OA
(3)2 = 5 xOA
9/5 = OA
1.8 cm = OA
IN ^ BAO ANGLE O IS 90 DEGREE,
AB2 = BO2 + AO2 (PYTHAGORAS THEOREM)
9 = BO2 + 3.24
9 - 3.24 = BO2
5.76 = BO2
v5.76= BO
2.4 = BO
VOLUME OF SMALL CONE IS
1/3 x 22/7 x (2.4)2 x 1.8
9.74 CU.METRES
VOLUME OF BIG CONE IS
1/3 x 22/7 x (2.4)2 x 3.2
17.32 CU.METERS
TOTAL VOLUME IS 27.06 CU.METERS
2007-02-05 05:06:28 · answer #5 · answered by Praveen K 1 · 0⤊ 0⤋
I had this comparable doubt in my innovations, in spite of the incontrovertible fact that it became sparkling for me. you may regulate and shop the three cones via reducing each and each cone into 2 of in basic terms one cone into 2 ... you in basic terms could shrink them with the intention to get the suitable shape of the cylinder!
2016-10-01 10:12:15 · answer #6 · answered by blasone 4 · 0⤊ 0⤋
area=1/3pi*r2*h
pi=3.14
r=3(4)
h=4(3)
therefore volume=
2007-02-04 06:40:16 · answer #7 · answered by quickanu 2 · 0⤊ 0⤋
volume of cone=1/3*3.14*r*r*h
here,
r=4
h=3
2007-02-04 04:31:59 · answer #8 · answered by kkp 1 · 0⤊ 1⤋
sorry i am confused as i am in hurry.
2007-02-04 04:33:12 · answer #9 · answered by sweetu 2 · 0⤊ 1⤋