An oil funnel made of tin sheet consists of a 10 cm long cylindrical portion attached to a frustum of a cone. If the total height is 22 cm, diameter of the cylindrical portion is 8 cm and the diameter of the top of the funnel is 18 cm, then find the area of the tin sheet required to make the funnel.
Height of the cylindrical portion, h = 10 cm,
height of the frustum of cone portion, H = 22 - 10 = 12 cm,
Radius of the cylindrical portion = Radius of smaller end of frustum portion,
Radius of larger end of frustum portion, R = 18/2 = 9 cm
Also, the slant height of the frustum, `l = sqrt(("R - r")^2 + "H"^2)`
`=sqrt((9 - 4)^2+12^2`
The area of the tin sheet required = CSA of frustum of cone + CSAA of cylinder
= π (R + r) l + 2πrh
≈ 782.57 cm2
So, the area of the tin sheet required to make the funnel is 782.57 cm2.