The sculpture is in the shape of a block letter 'C' with dimensions: 15 ft (height), 10 ft (width), 7 ft (depth), 4 ft (height of the inner curve), 4 ft (height of the outer curve), and 1 ft (thickness).
To find the surface area of the block letter 'C', we need to calculate the area of each of its sides and add them up.
1. Top surface: 10 ft x 7 ft = 70 ft^2
2. Bottom surface: 10 ft x 7 ft = 70 ft^2
3. Front surface (between the outer and inner curves): 4 ft x 10 ft = 40 ft^2
4. Back surface (between the outer and inner curves): 4 ft x 10 ft = 40 ft^2
5. Side surfaces (left and right sides between the outer and inner curves): 4 ft x 7 ft = 28 ft^2 (x2 for both sides = 56 ft^2)
Total surface area = 70 ft^2 + 70 ft^2 + 40 ft^2 + 40 ft^2 + 56 ft^2 = 276 ft^2
The surface area of the block letter 'C' sculpture is 276 square feet.