Question

A jokers cap is in the form of a right circular cone of base radius 7 cm and height 24 cm. Find the area of the sheet required to make 10 such caps.

Answer 1

Area of the cardboard required = Curved surface area of the cap (or cone)=`pi r l`
Now, `l=sqrt(r^(2)+h^(2))=sqrt(7^(2)+24^(2))=sqrt(49+576)=sqrt(625)=25 cm`
`implies" Curved surface area"=(22)/(7) xx 7 xx 25=550 cm^(2)`
` :. " Area of the cardboard required "=550 cm^(2)`.