To determine the surface area of the letter "C," we need more specific information about its dimensions, such as its height, width, depth (thickness), and the type of material it is made from. The surface area calculation will differ based on the actual geometric shape and proportions of the letter.
If you can provide the dimensions of the letter "C," like its height and width, as well as how thick it is, I can help calculate the surface area. Alternatively, if you have a specific shape in mind (like a block letter that resembles a rectangular prism), please describe that, and I can guide you on how to calculate its surface area accordingly.