To find the volume \( V \) of a rectangular prism using the formula \( V = B \times h \), we first need to determine the area of the base \( B \). The base area \( B \) is calculated by multiplying the length and width of the prism:
\[ B = \text{length} \times \text{width} = 714 , \text{m} \times 1012 , \text{m} \]
Now, let's calculate the area \( B \):
\[ B = 714 \times 1012 = 722568 , \text{m}^2 \]
Next, we multiply the base area \( B \) by the height \( h \) to find the volume \( V \):
\[ V = B \times h = 722568 , \text{m}^2 \times 1225 , \text{m} \]
Now we can calculate the volume \( V \):
\[ V = 722568 \times 1225 = 884307600 , \text{m}^3 \]
Now, to express this as a mixed number in simplest form, we can simplify \( 884307600 \). Since it is already a whole number, we can say:
\[ V = 884307600 , \text{m}^3 = 884307600 \frac{0}{1} \text{ m}^3 \]
Thus, the final answer is:
\[ \boxed{884307600 , \text{m}^3} \]
Note: This number does not need to be expressed as a mixed number since it's a whole number. It can also be left as is in cubic meters.