Circumference

• sextant

  A unit of angular distance equal to 60 degrees.

• straight angle

  An angle of 180 degrees.

Degree

• degree

  A measure for arcs and angles; "there are 360 degrees in a circle".

• minute

  A unit of angular distance equal to a 60th of a degree.

Radian

• milliradian

  A unit of angular distance equal to one thousandth of a radian.

• radian

  The unit of plane angle adopted under the Systeme International d'Unites; equal to the angle...

Also contains

• oxtant

  A unit of angular distance equal to half a quadrant.

• microradian

  A unit of angular distance equal to one thousandth of a milliradian.

• second

  A 60th part of a minute of arc; "the treasure is 2 minutes and 45 seconds south of here".

• mil

  An angular unit used in artillery; equal to 1/6400 of a complete revolution.

• grade

  One-hundredth of a right angle.

• steradian

  The unit of solid angle adopted under the Systeme International d'Unites.