what is the difference between total surface area and curved surface area?
The curved surface area is the areas of the faces(flat or curved) of the solid. Curved surface area of the solid does not include the area of the top and the area of the base of the solid.
Curved surface area of the cuboid = 2h( l + b)
Curved surface area of the cylinder = 2 rh. This the area of the curved portion of the cylinder.
Total surface area of any solid is the sum of areas of all the faces(flat or curved) of the solid.
Total surface area of the solid = Curved surface area of the solid + Surface area of the base + Surface area of the base
Total surface area of the cuboid = 2h( l + b) + 2 lb = 2( lh + bh + lb) . This the sum of the curved surface area and the areas of the top and base of the cuboid.
Curved surface area of the cylinder = 2 rh +
= 2
r ( r + h). This is the sum of the curved portion and the areas of the top and base area of the cylinder.