Relationship between two lines that meet at a right angle (90 degrees)
For other uses, see Perpendicular (disambiguation).
Geometry
Projecting a sphere to a plane
Outline
History (Timeline)
Branches
Euclidean
Non-Euclidean
Elliptic
Spherical
Hyperbolic
Non-Archimedean geometry
Projective
Affine
Synthetic
Analytic
Algebraic
Arithmetic
Diophantine
Differential
Riemannian
Symplectic
Discrete differential
Complex
Finite
Discrete/Combinatorial
Digital
Convex
Computational
Fractal
Incidence
Noncommutative geometry
Noncommutative algebraic geometry
Concepts
Features
Dimension
Straightedge and compass constructions
Angle
Curve
Diagonal
Orthogonality (Perpendicular)
Parallel
Vertex
Congruence
Similarity
Symmetry
Zero-dimensional
Point
One-dimensional
Line
segment
ray
Length
Two-dimensional
Plane
Area
Polygon
Triangle
Altitude
Hypotenuse
Pythagorean theorem
Parallelogram
Square
Rectangle
Rhombus
Rhomboid
Quadrilateral
Trapezoid
Kite
Circle
Diameter
Circumference
Area
Three-dimensional
Volume
Cube
cuboid
Cylinder
Dodecahedron
Icosahedron
Octahedron
Pyramid
Platonic Solid
Sphere
Tetrahedron
Four- / other-dimensional
Tesseract
Hypersphere
Geometers
by name
Aida
Aryabhata
Ahmes
Alhazen
Apollonius
Archimedes
Atiyah
Baudhayana
Bolyai
Brahmagupta
Cartan
Coxeter
Descartes
Euclid
Euler
Gauss
Gromov
Hilbert
Huygens
Jyeṣṭhadeva
Kātyāyana
Khayyám
Klein
Lobachevsky
Manava
Minkowski
Minggatu
Pascal
Pythagoras
Parameshvara
Poincaré
Riemann
Sakabe
Sijzi
al-Tusi
Veblen
Virasena
Yang Hui
al-Yasamin
Zhang
List of geometers
by period
BCE
Ahmes
Baudhayana
Manava
Pythagoras
Euclid
Archimedes
Apollonius
1–1400s
Zhang
Kātyāyana
Aryabhata
Brahmagupta
Virasena
Alhazen
Sijzi
Khayyám
al-Yasamin
al-Tusi
Yang Hui
Parameshvara
1400s–1700s
Jyeṣṭhadeva
Descartes
Pascal
Huygens
Minggatu
Euler
Sakabe
Aida
1700s–1900s
Gauss
Lobachevsky
Bolyai
Riemann
Klein
Poincaré
Hilbert
Minkowski
Cartan
Veblen
Coxeter
Present day
Atiyah
Gromov
v
t
e
In geometry, two geometric objects are perpendicular if their intersection forms right angles (angles that are 90 degrees or π/2 radians wide) at the point of intersection called a foot. The condition of perpendicularity may be represented graphically using the perpendicular symbol, ⟂. Perpendicular intersections can happen between two lines (or two line segments), between a line and a plane, and between two planes.
Perpendicularity is one particular instance of the more general mathematical concept of orthogonality; perpendicularity is the orthogonality of classical geometric objects. Thus, in advanced mathematics, the word "perpendicular" is sometimes used to describe much more complicated geometric orthogonality conditions, such as that between a surface and its normal vector.
A line is said to be perpendicular to another line if the two lines intersect at a right angle.[2] Explicitly, a first line is perpendicular to a second line if (1) the two lines meet; and (2) at the point of intersection the straight angle on one side of the first line is cut by the second line into two congruent angles. Perpendicularity can be shown to be symmetric, meaning if a first line is perpendicular to a second line, then the second line is also perpendicular to the first. For this reason, we may speak of two lines as being perpendicular (to each other) without specifying an order. A great example of perpendicularity can be seen in any compass, note the cardinal points; North, East, South, West (NESW)
The line N-S is perpendicular to the line W-E and the angles N-E, E-S, S-W and W-N are all 90° to one another.
Perpendicularity easily extends to segments and rays. For example, a line segment is perpendicular to a line segment if, when each is extended in both directions to form an infinite line, these two resulting lines are perpendicular in the sense above. In symbols, means line segment AB is perpendicular to line segment CD.[3]
A line is said to be perpendicular to a plane if it is perpendicular to every line in the plane that it intersects. This definition depends on the definition of perpendicularity between lines.
Two planes in space are said to be perpendicular if the dihedral angle at which they meet is a right angle.
called a foot. The condition of perpendicularity may be represented graphically using the perpendicular symbol, ⟂. Perpendicular intersections can happen between...
Perpendicular Gothic (also Perpendicular, Rectilinear, or Third Pointed) architecture was the third and final style of English Gothic architecture developed...
geometry, the perpendicular distance between two objects is the distance from one to the other, measured along a line that is perpendicular to one or both...
Perpendicular recording (or perpendicular magnetic recording, PMR), also known as conventional magnetic recording (CMR), is a technology for data recording...
bisector. The perpendicular bisector of a line segment is a line which meets the segment at its midpoint perpendicularly. The perpendicular bisector of...
Perpendicular plate can refer to: Perpendicular plate of ethmoid bone Perpendicular plate of palatine bone This disambiguation page lists articles associated...
Length between perpendiculars (often abbreviated as p/p, p.p., pp, LPP, LBP or Length BPP) is the length of a ship along the summer load line from the...
The perpendicular axis theorem (or plane figure theorem) states that, "The moment of inertia (Iz) of a laminar body about an axis (z) perpendicular to...
Decorated Gothic or Second Pointed (late 13th–late 14th centuries) Perpendicular Gothic or Third Pointed (14th–17th centuries) The architect and art...
Perpendicular bisector construction can refer to: Bisection § Line segment bisector, on the construction of the perpendicular bisector of a line segment...
Perpendicular Point Perpendicular Point is a small headland on the West Coast of New Zealand's South Island, overlooking the Tasman Sea. It lies about...
Point Perpendicular is a point at the southern tip of the Beecroft Peninsula and at the northern entry to Jervis Bay, in New South Wales, Australia. It...
similar-looking perpendicular symbol (⟂, \perp in LaTeX, U+27C2 in Unicode) is a binary relation symbol used to represent: Perpendicularity of lines in geometry...
curve, called the tangential component of the vector, and another one perpendicular to the curve, called the normal component of the vector. Similarly,...
The perpendicular plate of the ethmoid bone (vertical plate) is a thin, flattened lamina, polygonal in form, which descends from the under surface of...
any parallelogram with perpendicular diagonals (the second property) is a rhombus. In general, any quadrilateral with perpendicular diagonals, one of which...
W {\displaystyle W} . Informally, it is called the perp, short for perpendicular complement. It is a subspace of V {\displaystyle V} . Let V = ( R 5...
referring to the vertical perpendicular to a horizontal base line. Closely related and important geometrical concepts are perpendicular lines, meaning lines...
which the line segments between non-adjacent vertices are orthogonal (perpendicular) to each other. A kite is an orthodiagonal quadrilateral in which one...
other words, it is the intersection of the spheroid with the plane perpendicular to its axis of rotation and midway between its geographical poles. On...
regression becomes orthogonal regression: it minimizes the sum of squared perpendicular distances from the data points to the regression line. In this case...
In physics, a transverse wave is a wave that oscillates perpendicularly to the direction of the wave's advance. In contrast, a longitudinal wave travels...
length (equilateral). An equivalent condition is that the diagonals perpendicularly bisect each other. Informally: "a pushed-over square" (but strictly...
every such parabola is the graph of a quadratic function. The line perpendicular to the directrix and passing through the focus (that is, the line that...
Europe saw tracery patterns resembling lace develop, while in England Perpendicular Gothic or Third Pointed preferred plainer vertical mullions and transoms...
Caliper, micrometer, tools for measuring diameters Conjugate diameters – Perpendicular diameters of a circle or hyperbolic-orthogonal diameters of a hyperbola...
coordinates, which are the signed distances to the point from two fixed perpendicular oriented lines, called coordinate lines, coordinate axes or just axes...