The radius and height of a cone are in the ratio 4:3. The area of the base is `154 c m^2dot` Find the area of the curved surface. l

Explanation

et radius r`=4x cm`
height h`=3x cm`
area of the base`=154cm^2`
`pir^2=154cm^2`
`r=7cm`
but we have `r=4x`so `x=7/4`
`h=21/4cm`
so slant height`=(r^2+h^2)^(1/2)=7/4(10)^(1/2)`
so curved surface area`=pixx(7/4)xx(7/4)(10)^(1/2)`
`=(49/16)pi(10)^(1/2)`