# The angle of 1" (second of arc) in a radian is equal to: (1) 4.85 × 10–4 (2) 4.85 × 10–6 (3) 1.75 × 10–2 (4) 1.75 × 10–4

The angle of 1" (second of arc) in a radian is equal to:

(1) 4.85 × 10–4
(2) 4.85 × 10–6
(3) 1.75 × 10–2
(4) 1.75 × 10–4

A minute of arc is $$π\over 10800$$ of a radian.
A second of arc, arcsecond (arcsec), or arc second, denoted by the symbol ″, is $$1\over60$$ of an arcminute, $$1\over3600$$ of a degree, $$1\over1296000$$of a turn, and $$π\over648000$$ (about $$1\over206369$$)