3. the luxor hotel, in las vegas, is a square pyramid with lateral faces consisting of black, glassed mirrored panes. the building is 646 feet wide at the base and 350 feet high. how much glass was needed to cover the pyramid?

Given: 
Square pyramid with lateral faces.
646 ft wide at the base.
350 ft high.

Because of the term lateral faces, we need to get the lateral area of the square pyramid.

Lateral Area = a √a² + 4 h² ; a = 646 ft ; h = 350 ft

L.A. = 646 ft √(646ft)² + 4 (350ft)²
L.A. = 646 ft √417,316 ft² + 4 (122,500 ft²)
L.A. = 646 ft √417,316 ft² + 490,000 ft²
L.A. = 646 ft √907,316 ft²
L.A. = 646 ft * 952.53 ft
L.A. = 615,334.38 ft²

(6,0) i hope it makes enough sense