Complex sentence: There are 2000π milliradians (≈ 6283.185 mrad) in a circle; thus a milliradian is just under 1 ⁄ 6283 of a circle, or ≈ 3.438 minutes of arc.
Split into simpler sentences: There are 2000π milliradians (≈ 6283.185 mrad) in a circle. So a milliradian is just under 1 ⁄ 6283 of a circle, or ≈ 3.438 minutes of arc.