The volume of a square pyramid is given by the equation:

Where B is the area of the base and His the high of the pyramid, the area of the square base can be calculated with the formula:

Where L is the length of the sides of the square, let's calculate it for our figure, like this:

And now, let's calculate the volume of the pyramid with the first formula, like this:

Then, the volume of the pyramid is 405,3 cubic inches