This page contains a list of user images about Right Angle which are relevant to the point and besides images, you can also use the tabs in the bottom to browse Right Angle news, videos, wiki information, tweets, documents and weblinks.
Right Angle Images
Music video by Rihanna performing Take A Bow. YouTube view counts pre-VEVO: 66288884. (C) 2008 The Island Def Jam Music Group.
A substitute teacher from the inner city refuses to be messed with while taking attendance.
Watch Season 1 of Mortal Kombat Legacy here: http://www.youtube.com/channel/SWVkIoQKmEa4I The Mortal Kombat Legacy continues in Season 2 as Liu Kang, Kung La...
Music video by P!nk performing Try (The Truth About Love - Live From Los Angeles). (C) 2012 RCA Records, a division of Sony Music Entertainment.
"Just One Last Time" feat. Taped Rai. Available to download on iTunes including remixes of : Tiësto, HARD ROCK SOFA & Deniz Koyu http://smarturl.it/DGJustOne...
YOLO is available on iTunes now! http://smarturl.it/lonelyIslandYolo New album coming soon... Check out the awesome band the music in YOLO is sampled from Th...
Macklemore & Ryan Lewis present the official music video for Can't Hold Us feat. Ray Dalton. Can't Hold Us on iTunes: https://itunes.apple.com/us/album/cant-...
This video accidentally turned out kind of sad, ME SO SOWWY IT NOT POSED TO BE SAD WHO WANTS HUGS AND COOKIES? Also, FYI for anyone attempting this, it takes...
Fun.'s music video for 'We Are Young' featuring Janelle Monáe from the full-length album, Some Nights - available now on Fueled By Ramen. Visit http://ournam...
What people expect romance to be vs what it really is... Follow Catherine! https://twitter.com/CDekoekkoek Check out my 2nd Channel for more vlogs: http://ww...
Jimmy reveals that he is f*@#ing Ben Affleck.
Music video by Eminem performing Love The Way You Lie. © 2010 Aftermath Records #VEVOCertified on September 13, 2011. http://www.vevo.com/certified http://ww...
In geometry and trigonometry, a right angle is an angle that bisects the angle formed by two halves of a straight line. More precisely, if a ray is placed so that its endpoint is on a line and the adjacent angles are equal, then they are right angles. As a rotation, a right angle corresponds to a quarter turn (that is, a quarter of a full circle).
Closely related and important geometrical concepts are perpendicular lines, meaning lines that form right angles at their point of intersection, and orthogonality, which is the property of forming right angles, usually applied to vectors. The presence of a right angle in a triangle is the defining factor for right triangles, making the right angles basic to trigonometry.
In Unicode, the symbol for a right angle is U+221F ∟ right angle (HTML:
∟). Variations are U+299C ⦜ right angle variant with square and U+299D ⦝ measured right angle with dot and U+22BE ⊾ right angle with arc.
In diagrams the fact that an angle is a right angle is usually expressed by adding small right angle that forms a square with the angle in the diagram, as seen the diagram of a right triangle to the right. Other variants include having a curved angle, but with a small dot in the angle field.
Right angles are fundamental in Euclid's Elements. They are defined in Book 1, definition 10, which also defines perpendicular lines. Euclid uses right angles in definitions 11 and 12 to define acute angles (those smaller than a right angle) and obtuse angles (those greater than a right angle). Two angles are called complementary if their sum is a right angle.
Book 1 Postulate 4 states that all right angles are equal, which allows Euclid to use a right angle as a unit to measure other angles with. Euclid's commentator Proclus gave a proof of this postulate using the previous postulates, but it may be argued that this proof makes use of some hidden assumptions. Saccheri gave a proof as well but using a more explicit assumption. In Hilbert's axiomatization of geometry this statement is given as a theorem, but only after much groundwork. One may argue that, even if postulate 4 can be proven from the preceding ones, in the order that Euclid presents his material it is necessary to include it since without it postulate 5, which uses the right angle as a unit of measure, makes no sense.
Conversion to other units 
A right angle may be expressed in different units:
- 1/4 turn.
- 90° (degrees)
- π/2 or τ/4 radians
- 100 grad (also called grade, gradian, or gon)
- 8 points (of a 32-point compass rose)
- 6 hours (astronomical hour angle)
Rule of 3-4-5 
Throughout history carpenters and masons have known a quick way to confirm if an angle is a true "right angle." It is based on the most widely known Pythagorean triple (3, 4, 5) and so called the "Rule of 3-4-5." From the angle in question, running a straight line along one side exactly three units in length, and along the second side exactly four units in length, will create a hypotenuse (the longer line opposite the right angle that connects the two measured endpoints) of exactly 5 units in length. This measurement can be made quickly and without technical instruments. The geometric law behind the measurement is the Pythagorean theorem ("The square of the hypotenuse of a right triangle is equal to the sum of the squares of the two adjacent sides").
Thales' theorem 
Thales' theorem states that an angle inscribed in a semicircle is a right angle.
See also 
|Wikimedia Commons has media related to: Right angles|