Here we need to use the formula of volume of triangular pyramid, which is
[tex] V =\frac{bh}{3} [/tex]
here b is the area of the base and h is the height of the pyramid .
First we need the value of b. The base is a square with edge length 706 feet. And area of square is side square. So we will get
[tex] b=706^2 = 498436 [/tex]
Now we need to substitute the value of b in the formula of volume .
[tex] V =\frac{498436*470}{3}=78088306.7 ft^3 [/tex]
