Final answer:
The surface area of the four triangular faces of the Louvre Museum entrance pyramid is 21293.6 square feet.
Step-by-step explanation:
To find the surface area of the four triangular faces of the pyramid, we need to calculate the area of one triangular face and then multiply it by 4. The area of a triangle can be calculated using the formula A = (1/2)bh, where A is the area, b is the base length, and h is the height. In this case, the base length is 116 feet and the height is 91.7 feet.
Plugging the values into the formula, we get A = (1/2)(116)(91.7) = 5323.4 square feet for one triangular face. To find the surface area of all four triangular faces, we multiply this value by 4: 5323.4 * 4 = 21293.6 square feet.