(a)

The surface area of a spherical segment. radius of the sphere and the height is , the upper and lower radii and respectively,

The zone is a surface of revolution about -axis, so the surface area is given by

In the -plane, the equation of the zone is simply that of a circle is .

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\ \ .

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(b)

For a cylinder with radius and the height is with an axis along the -axis.

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The surface area is given by .

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