Quadrangle ( geography ) - wikipedia Quadrangle ( geography ) New York ( Essex County ) Mt. Marcy : an 1892 USGS quadrangle map ( or topographic sheet ) of the Mount Marcy area of the Adirondacks in New York State from the first decades of the United States Geological Survey. In geology or geography, the word `` quadrangle '' usually refers to a United States Geological Survey ( USGS ) 7.5 - minute quadrangle map, which are usually named after a local physiographic feature. The shorthand `` quad '' is also used, especially with the name of the map ; for example, `` the Ranger Creek, Texas quad map ''. These maps are one - quarter of the older 15 - minute series. On a quadrangle map, the north and south limits of the quadrangle are not straight lines, but are actually curved to match Earth 's lines of latitude on the standard projection. The east and west limits are usually not parallel as they match Earth 's lines of longitude. In the United States, a 7.5 minute quadrangle map covers an area of 49 to 70 square miles ( 130 to 180 km ). The surfaces of other planets have also been divided into quadrangles by the USGS. Martian quadrangles are also named after local features. Quadrangles that lie on the pole of a body are also sometimes called `` areas '' instead, since they are circular rather than four - sided. See also World Geographic Reference System ( GEOREF ) on aeronautical charts List of quadrangles on Mercury List of quadrangles on Venus List of quadrangles on the Moon List of quadrangles on Mars List of quadrangles on Tethys, a moon of Saturn List of quadrangles on Europa, a moon of Jupiter Quadrilateral References Jump up ^ Map Scales, Fact Sheet FS105 - 02, ( February 2002 ) Jump up ^ Morton, Oliver ( 2002 ). Mapping Mars : Science, Imagination, and the Birth of a World. New York : Picador USA. p. 98. ISBN 0 - 312 - 24551 - 3. Retrieved from `` https://en.wikipedia.org/w/index.php?title=Quadrangle_(geography)&oldid=759250591 '' Categories : Cartography Talk About Wikipedia Català Italiano Українська Edit links This page was last edited on 10 January 2017, at 02 : 28. About Wikipedia

Question: why is it called a 7.5 minute map
Answer: maps are one-quarter of the older 15-minute series