The lateral surface area of the pyramids in question is given by
1/2 * perimeter * slant height
Using the values of 481' for the height and 754' base per side
1/2 * 754 * 4 * slant height
Our old buddy the Pythagorean theorem can be used to find the slant height
a^2 + b^2 = c^2
so
481^2 + (754/2)^2 = c^2
c = sqrt(231361 + 142129) = sqrt(373490) = 611
and then
1/2 * 754 * 4 * 611 = 921388 square feet.
If each stone was only a square foot and we layed them end to end, they would stretch for about 175 miles!
Apologies in advance for errors in calculation or reasoning.
