Slant height of the cone , `l = sqrt((12)^2 + (5)^2)` = 13 cm.

Lateral surface of the solid  = Curved surface of cone + Curved surface of cylinder + Surface area of bottom .

                                              = `pi r l + 2 pi r h + pi r^2, `          Where  h is the height of the cylinder.

                                             = ` pi r ( l + h + r)`

                                             = `[22/7 xx 12 xx ( 13 + 18 + 12)] cm^2`

                                             = ` (22/7 xx 12 xx 43) cm^2`

                                            = `(11352/7)  cm^2`

                                            = ` 1621 5/7 cm^2`