How much metal sheet is required to prepare a cylindrical pipe 10 cm long and radius 7 cm?

Find the area of the iron sheet required to prepare a cone 20 cm high with base radius 21 cm.

The difference between the outside and the inside surface area of a cylindrical pipe 14 cm long is 44 cm^2 . The pipe is made of 99 cm^3 of metal. If R is the outer radius and r is the inner radius of the pipe, then what is (R + r) equal to?

An oil funnel of tin sheet consists of a cylindrical portion 10 cm long attached to a frustum of a cone. If the total height is 22 cm, the diameter of the cylindrical portion be 8 cm and the diameter of the top of the funnel be 18 cm, then find the area of the tin sheet required to make the funnel.

An oil funnel made of tin sheet consists of a cylindrical portion 10 cm long 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, find the area of the tin sheet required to make the funnel.

The difference between outside and inside surface areas of cylindrical metallic pipe 14cm long is 44cm^(2). If the pipe is made of 99cm^(2) of metal,find the outer and inner radii of the pipe