a) the base is a square to find its area you can use the formula:

a being the area and s one of the sides
now just use s= 55ft

The area of the base is 3025 ft^2
b) the volume of the pyramid is:

v being the volume, b the area of the base and h the height of the pyramid
use b=3025 and h=460

the volume of the pyramid is 463833.3 ft^3