A heap of wheat is in the form of a cone whose diameter is 10.5 m and height is 3 m. Find its volume. The heap is to be covered by canvas to protect it from rain. Find the area of the canvas required

Explanation

Radius of heap `r=(10.5/2)m=5.25`
Height of heap`h=3m`
Volume of cone`=(1/3)pir^2h`
`(1/3)xx(22/7)xx(105/2)xx(105/2)xx3`
`=(22xx105xx105xx3)/(3xx20xx20xx7)`
`V=86.625 m^3`
Area of the canvas`=`surface area of cone`=pirl`
Slant height `l=sqrt(h^2+r^2)`
`l=sqrt(32+(10.5/2)^2)`
`l=sqrt(9+ (110.25/4))`
`l=sqrt(146.25/4)`
`l=sqrt36.56`
`l=6.05 m` (approx.)
Surface area of cone`=pirl`
`=pixx(105/20)xx6.05`
`= (22/7) xx(635.25/20)`
`= 99.82 m^2`
`therefore` Its volume `V=86.625 m^3`
The area of the canvas required `= 99.82 m^2`