The outside of the table represents the circumference and the formula for circumference is diameter times pi (simplified to 3.14). diameter is two times the radius so in this case we multiply 2 1/4 or 2.25 by two and we get 4 1/2 or 4.5. Now that we have the diameter, just multiply by 3.14 to get 14.13 feet for the circumference (: