I doubt the surface area of the bollard involves the bottom circular surface, since the question asks for the sides and the top. I presume that a typical bollard is designed to be placed on the ground such that the bottom surface is not exposed to the surroundings. Typical example of bollards include those near traffic light designated crossing areas.

Thanks Eric,
Think your point is correct. I have doubts when question mentioning area of the sides and top of bollards. I understand the meaning now :)

Answer for b) surface area should be 8014..19 cm^2. Shouldn’t include the base circular area (pixr^2=797.14).

thx!!