The volume of a pyramid can be calculated with the following formula:
[tex]\text{volume =}\frac{1}{3}\times(area\text{ of base)}\times height[/tex]
The base of the pyramid is a square, so its area will be:
[tex]\begin{gathered} \text{area of base =side}\times side \\ \text{area of the base=706}\times706 \\ \text{area of base =}498,436\text{ ft²} \end{gathered}[/tex]
Let's plug that result in the formula for the volume:
[tex]\begin{gathered} \text{volume}=\frac{1}{3}\times(498,496)\times448 \\ \text{volume}=74,433,109\text{ ft³} \end{gathered}[/tex]
So our final answer will be:
[tex]\text{volume = 74,433,109 ft}^3[/tex]