Answer:
see the attachment
Step-by-step explanation:
The area of one circular end of the cylinder is given by the formula
A = π·r^2
where r is the radius (half the diameter).
The lateral area of the cylinder is given by the formula
A = 2π·r·h
where r is the radius (half the diameter) and h is the height.
The total surface area is that of two (2) ends plus the lateral area.
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When there are a number of similar problems to do, it is convenient to use a calculator or spreadsheet, putting the dimensions in a list and letting the formulas be evaluated automatically.
The attached spreadsheet shows the lateral area and total surface area of each of the cylinders in the figure. (Pay attention to problem number.) The radius for problem 19 is not visible, so we made a guess. It is of no consequence, since it is not a problem you asked about.
The formula in the formula bar of the figure shows the calculation of lateral area. The units of area are filled in by hand from the dimensions in the figures.
