IV.

Other Angular Measurements

In advanced branches of mathematics, especially those involving calculus, angles are usually measured in units called radians (rad). There are 2 p rad, or about 6.28 rad, in 360°.

In military usage, angles are usually measured in mils, especially for artillery aiming. A mil is the measure of a central angle subtended by an arc that is 1/6400 of the circle. One mil equals 0.05625° and is approximately 0.001 rad.