**17**. Calculate the surface Area of the following closed cylinder.

**18**. Calculate the surface Area of the following closed cuboids.

**19**. Find the surface area of the following figures.

**20**. Find the outer surface area of a box with the following dimensions; Length 30 mm, width 16 mm and height 60 mm.

**21**. Find the surface area of each of the following figures. (Take pi as 3.14)

**22**. A metal rod 60 cm long has a diameter of 1.4 cm. Find its surface area.

**23**. A cardboard map holder is in the shape of a cylinder open at one end. If it has a radius of 8.4 cm and a height of 60 cm. What is its outer surface area?

**24**. A petrol drum is 2.5 m long and has a diameter of 60 cm. If a drum is rolled in a straight line until it completes 100 revolutions, What area will it cover? Pi = 3.14.

**25**. A 4 m long cylinder has a volume of 98.56 m^{3} Calculate its surface area if it is closed on both ends.

**26**. The surface area of a closed cylinder is 2112 cm^{2}. If the radius of the cylinder is 14 cm, work out its height. \((\pi = {22\over7})\)