Preparing the working area ensures cleanliness, safety, and efficiency during treatment. It minimizes infection risks, organizes necessary tools, and creates a comfortable environment for the practitioner and patient, supporting a smooth and effective treatment process.
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.