Conical cavity is drilled in a circular cylinder of height 15 cm and base radius 8 cm. The height and base of the radius of the cone are al…

⇒ l = $(\sqrt {{r^2} + \;{h^2}} \; = \;\sqrt {{{15}^2} + \;{8^2}} \; = \;17\;cm)$

here, l = slant height of cylinder

r = radius of cylinder

h = height of cylinder

⇒ Total remaining surface area = $(2\pi rh + \;\pi {r^2} + \;\pi rl)$

⇒ 2π × 8 × 15 + π × 64 + π × 136

⇒ 440π cm2