The total surface area of a cone of radius `r/2` and length `2l ,` is a)`2pir(l+r)`b)`pir(l+r/4)` c)`pir(l+r)` d)`2pirl`

Explanation

Given, radius of a cone is `r/2`

slant height=2l

T.S.A of a cone = `(pi)r(r+L)`

T.S.A of a cone = `(pi)(r/2)(r/2)+2l)`

T.S.A of a cone = `(pi)(r)(l+r/4)`

Hence, option(b) is correct.