The diameter is 0.286". Which, by the way, does not correspond to any standard size drill in English or metric units, but that's what it is. If there is an explanation for this I haven't seen it.
CD's have a diameter of 5.5 centimeters;)
15 mm
believe to be 12..
The center of the rim is 66.1mm in diameter on a 2005-2008 Nissan Frontier.
Generally an LP is 12" in diameter.
The 45 RPM record was developed by RCA Victor in 1949 as a competing format for the 33 1/3 RPM (33) format of rival Columbia records that premiered in 1948. Eventually the 45 RPM format (7 inches in diameter with a one-inch center hole) was adopted for shorter recordings while 33 RPM (12 inches in diameter with a 1/4 inch center hole) was used for so called LP (long playing) albums. This eliminated the need to reduce the groove width or quality of 45 RPM recordings.
It is to mark it as either promo or clearance. On LP's they would clip a corner of the jacket. If the 45 Lp's have the small additional hole in the same location, though they are from different recording companies could there be another purpose for it other than to denote a promo record. Such as a alignment hole of some type?
Lansing in the center of the LP.
4.24563 inches is the diameter of a golf hole.
It is 6 inches in diameter located in the center of the board and 9 inches from the top of the board to the center of the hole. For cornhole board design ideas check out: http://www.cornholeace.com/cornhole-board-designs.php
The cord of a circle that contains the center of that circle is a diameter of that circle.
The "diameter" of a black hole is usually taken as the diameter of the event horizon.