The arcsecond (″) equals 1/3,600 of a degree, providing extremely fine angular resolution for astronomy, optics, and satellite imaging. The Hubble Space Telescope has a resolution of about 0.05 arcseconds, and stellar parallax measurements use milliarcsecond precision. One arcsecond equals 1/3600 degree or about 0.00000485 radians.

A turn (tr), also called a revolution, represents one complete rotation of 360 degrees or 2π radians. It is used in engineering contexts involving rotational mechanics, electric motor specifications, and angular velocity calculations where whole rotations are more intuitive than degrees or radians. One turn equals exactly 360 degrees.