What is the length of the circumference 1.5?

The circumference of a circle is calculated using the formula ( C = 2\pi r ), where ( r ) is the radius. If you mean that the radius is 1.5 units, then the circumference would be approximately ( 2\pi \times 1.5 \approx 9.42 ) units. If you are referring to a diameter of 1.5 units, then the circumference would be ( \pi \times 1.5 \approx 4.71 ) units. Please clarify if you meant the radius or diameter for an accurate answer.