The entrance to the louvre museum in paris, france, is a square pyramid. the side length of the base is 116 feet, and the height of one of the triangular faces is 91.7 feet. find the surface area of the four triangular faces of the entrance to the louvre museum

The length of the base of any of the triangular faces is 91.7 ft, and the height of that face is 91.7 ft, measured from this base to the pinnacle (vertex).

The area of this one face is thus A = bh/2, which comes out to 
A=(116 ft)(91.7 ft)/2.  Multiply this result by four:

Total A = 4(116)(91.7)/2) = 21274 sq ft (where I have rounded off the answer to the nearest unit).

Well if you have 20 bats you probably want 20 balls? you don’t have enough context to answer the question.