Advertisements
Advertisements
प्रश्न
The total surface area of a cone of radius `r/2` and length 2l, is
विकल्प
`2 pi r (1 + r)`
` pi r (1 + r/4)`
`pi r (1+ r) `
` 2 pi rl`
उत्तर
The formula of the total surface area of a cone with base radius ‘r’ and slant height ‘l’ is given as
Total Surface Area = `pi r(l+r)`
Here it is given that the base radius is ‘`r/2`’ and that the slant height is ‘2l’.
Substituting these values in the above equation we have
Total Surface Area = `pi (r/2)(2l+r/2)`
= `pir(l+r/4)`
APPEARS IN
संबंधित प्रश्न
If the volume of a right circular cone of height 9 cm is 48π cm3, find the diameter of its base.
Find the length of cloth used in making a conical pandal of height 100 m and base radius 240 m, if the cloth is 100 π m wide.
If the height and radius of a cone of volume V are doubled, then the volume of the cone, is
If a cone is cut into two parts by a horizontal plane passing through the mid-point of its axis, the axis, the ratio of the volumes of upper and lower part is
Find the volume of a cone, if its total surface area is 7128 sq. cm and radius of base is 28 cm. `(π = 22/7)`
Volume of a cone is 6280 cubic cm and base radius of the cone is 20 cm. Find its perpendicular height. (π = 3.14)
In a field, dry fodder for the cattle is heaped in a conical shape. The height of the cone is 2.1m. and diameter of base is 7.2 m. Find the volume of the fodder. if it is to be covered by polythin in rainy season then how much minimum polythin sheet is needed ?
`( π = 22/7 ) and sqrt 17.37 = 4.17`
If the radius of the base of a cone is tripled and the height is doubled then the volume is
In a right circular cone, height, radius and slant height do not always be sides of a right triangle.
A right triangle with sides 6 cm, 8 cm and 10 cm is revolved about the side 8 cm. Find the volume and the curved surface of the solid so formed.
