The angular floor plan in retail design provides several advantages:
1. Better traffic flow: This design ensures smooth movement of customers within the store, avoiding congestion and enhancing the shopping experience.
2. Maximized space usage: Angular layouts allow for better use of the space available, creating more opportunities for product displays and customer engagement.
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.