Search results
Results from the WOW.Com Content Network
In a triangle, four basic types of sets of concurrent lines are altitudes, angle bisectors, medians, and perpendicular bisectors: A triangle's altitudes run from each vertex and meet the opposite side at a right angle. The point where the three altitudes meet is the orthocenter.
In mathematics, a conformal map is a function that locally preserves angles, but not necessarily lengths.. More formally, let and be open subsets of .A function : is called conformal (or angle-preserving) at a point if it preserves angles between directed curves through , as well as preserving orientation.
In China, Pei Xiu (224–271) identified "measuring right angles and acute angles" as the fifth of his six principles for accurate map-making, necessary to accurately establish distances, [5] while Liu Hui (c. 263) gives a version of the calculation above, for measuring perpendicular distances to inaccessible places.
See the figures in this article for examples. The three defining points may also identify angles in geometric figures. For example, the angle with vertex A formed by the rays AB and AC (that is, the half-lines from point A through points B and C) is denoted ∠BAC or ^. Where there is no risk of confusion, the angle may sometimes be referred to ...
In the case of an acute triangle, all three of these segments lie entirely in the triangle's interior, and so they intersect in the interior. But for an obtuse triangle, the altitudes from the two acute angles intersect only the extensions of the opposite sides. These altitudes fall entirely outside the triangle, resulting in their intersection ...
Triangulation may be used to find the position of the ship when the positions of A and B are known. An observer at A measures the angle α, while the observer at B measures β. The position of any vertex of a triangle can be calculated if the position of one side, and two angles, are known.
There are angles that are not constructible but are trisectible (despite the one-third angle itself being non-constructible). For example, 3 π / 7 is such an angle: five angles of measure 3 π / 7 combine to make an angle of measure 15 π / 7 , which is a full circle plus the desired π / 7 .
Möbius geometry is the study of "Euclidean space with a point added at infinity", or a "Minkowski (or pseudo-Euclidean) space with a null cone added at infinity".That is, the setting is a compactification of a familiar space; the geometry is concerned with the implications of preserving angles.