To find the approximate circumference of a circle, the formula used is:
\[ C \approx 2 \cdot \pi \cdot r \]
Where \( C \) is the circumference and \( r \) is the radius of the circle. In this case, the radius is 450.
Using \( \pi \approx 3.14 \), the correct formula for the circumference would therefore be:
\[ C \approx 2 \cdot 3.14 \cdot 450 \]
From the options provided, the correct choice is:
C≈2⋅3.14⋅450