21.21 millimeters wide
Diameter 17.91 mm (0.705 in) It is 17.91 mm (0.705 in) in diameter
The diameter of a basketball ring is 45.72 centimeters.
A millimetre is a unit of measurement of length. A diameter is not. The question, therefore, makes no sense.
80 millimeters is 3.15 inches.
The sun is not millimeters. It is a G-type star, on the Main Sequence, in mid-life. For its spectral classification, its size is average, with a diameter of about 1,390,000,000,000 millimeters
10 millimeters is 0.39 inches.
(1,000)/(diameter of one M in millimeters)
A standard sized can of soup is 108 millimetres high. It has a diameter of 75 mm.