# Calculate the angle of (a)1o(degree) (b)1′ (minute of arc or arcmin) and (c)1′′(second of arc of arc second) in radians.

Use 360o=2π rad, 1o=60′ and 1′=60′′

We know that 3600=2π rad

⇒10=(π180)rad=0.0175rad

⇒1′=(160)=π60×180=0.00029rad

⇒1"=(13600)=π3600×180=0.0000048rad