Calculate the angle of (a) 1° (degree) (b) 1' (minute of arc or arcmin) and (c) 1"(second of arc or arc second) in radians.

a)

360° = 2π radian

1° = 2π/360 radian

So, 1° = π/1800 radian

b)

1' minute = 1°/60 = 1/60 x π/180 radian

= π/10800 radian

c)

1 sec = 1’/60 = 1/60 x 1/60 x 1°

= 1/3600 x π/180 radian

= 1/648000 radian

· 1=180

· 1' minute = π /10800 radian

· 1 sec = 1/648000 radian