Amphoteric oxides are compounds that can act as both acidic and basic oxides. These oxides can react with both acids and bases, depending on the conditions. In acidic environments, they behave as bases, and in basic environments, they act as acids.
Two examples of amphoteric oxides are:
On the day of her examination, Riya sharpened her pencil from both ends as shown below. 
The diameter of the cylindrical and conical part of the pencil is 4.2 mm. If the height of each conical part is 2.8 mm and the length of the entire pencil is 105.6 mm, find the total surface area of the pencil.
