Question
Find the slant height , volume , curved surface area and the whole surface area of a cone of radius 21 cm and height 28 cm.
Answer: Option A
Was this answer helpful ?
Here , r = 21 cm and h = 28 cm.
`:.` Slant height , ` l = sqrt(r^2 + h^2) = sqrt((21)^2 + (28)^2) = sqrt(1225)` = 35 cm.
Volume = `1/3 pi r^2 h` =` (1/3 xx 22/7 21 xx 21 xx 28) cm^3` = 12936` cm^3`
Curved surface area =` pi r l =( 22/7 xx 21 xx 35) cm^2` = 2310` cm^2`
Total surface area =` ( pi r l + pi r^2)`
=`( 2310 + 22/7 xx 21 xx 21 ) cm^2 = 3696 cm^2`
Was this answer helpful ?
More Questions on This Topic :
Latest Videos
Latest Test Papers
Submit Solution