To find the total surface area of the tent, add up the surface area of each face:

Surface area of triangular base: 1/2 * 4.75ft * 3ft = 7.125 square feet
Surface area of front rectangle face: 4.75ft * 4ft = 19 square feet
Surface area of back rectangle face: 4.75ft * 4ft = 19 square feet

Total surface area of the tent: 7.125 + 19 + 19 = 45.125 square feet

So, you would need 45.125 square feet of fabric to make the tent.

If you need to account for sewing allowance or extra fabric for hems and seams, it's recommended to add an additional percentage to the total surface area to ensure you have enough material for the project.