Volume of Cone

Volume of Cone : From the above diagram we can see that there is right circular cylinder and a right circular cone of the same base radius and same height.
When fill up cone up to the brim is emptied into the cylinder 3 times then the cylinder will be completely filled up to the brim. So from that we can conclude that cone volume is 1/3 rd that of the volume of the cylinder.
The formula is :
volume of - cone = 1/3 π r2 h
l2 = r2 + h2
|
Some solved examples :
1) Find the volume of a cone the radius of whose base is 21 cm and height is 28 cm.
Solution : r = 21 cm and h = 28 cm
Volume of cone = 1/3 π r
2 h
V = 1/3 ( 3.14 x 21 x 21 x 28)
V = 1/3 x 38772.72
∴ Volume of a cone = 12924.24 cm
3
_________________________________________________________________
2) If the height of a cone is 15 cm and its volume is 770 cu.cm; find the radius of its base.
Solution : h = 15 cm and V = 770 cu.cm
volume of cone = 1/3 π r
2 h
⇒ 770 = 1/3 x 3.14 x r
2 x 15
⇒ 770 = 3.14 x r
2 x 5
⇒ 770 = 15.7 x r
2
⇒ r
2 = 770 / 15.7 = 49
⇒
2 = 49
∴ r = 7 cm.
_________________________________________________________________
3) A right triangle ABC with sides 5 cm, 12 cm and 13 cm is revolved about the side 12 cm. Find the volume of the solid so obtained.
Solution : As the triangle revolved about the side 12 cm.
∴ radius = r = 5m and height = h = 12 cm
Volume = 1/ 3 π r
2 h
V = 1/3 x 3.14 x 5 x 5 x 12
V = 314 cm
3
Volume :
• Volume Formulas
• Volume of Irregular Shape
• Volume of a Cube
• Volume of a Rectangular Prism(Cuboid)
• Volume of a Cylinder
• Volume of Cone
• Volume of a Sphere
• Volume of a Hemisphere
• Volume of a Prism
• Volume of a Pyramid
To Mensuration
Home Page