# Category: Geometric shapes

Paper bag problem
In geometry, the paper bag problem or teabag problem is to calculate the maximum possible inflated volume of an initially flat sealed rectangular bag which has the same shape as a cushion or pillow, m
Stripe (pattern)
A stripe is a line or band that differs in color or tone from an adjacent area. Stripes are a group of such lines.
Bistable structure
In mechanical engineering, a bistable structure is one that has two stable mechanical shapes, particularly where they are stabilized by different curvature axes. A common example of a bistable structu
Equidimensional
Equidimensional is an adjective applied to objects that have nearly the same size or spread in multiple directions. As a mathematical concept, it may be applied to objects that extend across any numbe
Statistical shape analysis
Statistical shape analysis is an analysis of the geometrical properties of some given set of shapes by statistical methods. For instance, it could be used to quantify differences between male and fema
Triple helix
In the fields of geometry and biochemistry, a triple helix (plural triple helices) is a set of three congruent geometrical helices with the same axis, differing by a translation along the axis. This m
Body of constant brightness
In convex geometry, a body of constant brightness is a three-dimensional convex set all of whose two-dimensional projections have equal area. A sphere is a body of constant brightness, but others exis
Conoid
In geometry a conoid (from Greek κωνος 'cone', and -ειδης 'similar') is a ruled surface, whose rulings (lines) fulfill the additional conditions: (1) All rulings are parallel to a plane, the directrix
Lemon (geometry)
In geometry, a lemon is a geometric shape, constructed as the surface of revolution of a circular arc of angle less than half of a full circle, rotated about an axis passing through the endpoints of t
Convex cone
In linear algebra, a cone—sometimes called a linear cone for distinguishing it from other sorts of cones—is a subset of a vector space that is closed under scalar multiplication; that is, C is a cone
Fusiform
Fusiform means having a spindle-like shape that is wide in the middle and tapers at both ends. It is similar to the lemon-shape, but often implies a focal broadening of a structure that continues from
Plücker's conoid
In geometry, Plücker's conoid is a ruled surface named after the German mathematician Julius Plücker. It is also called a conical wedge or cylindroid; however, the latter name is ambiguous, as "cylind
Geometric Shapes (Unicode block)
Geometric Shapes is a Unicode block of 96 symbols at code point range U+25A0–25FF.
Serpentine shape
A serpentine shape is any of certain curved shapes of an object or design, which are suggestive of the shape of a snake (the adjective "serpentine" is derived from the word serpent). Serpentine shapes
Ellipsoid
An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface;  that
Shape
A shape or figure is a graphical representation of an object or its external boundary, outline, or external surface, as opposed to other properties such as color, texture, or material type.A plane sha
Parbelos
The parbelos is a figure similar to the arbelos but instead of three half circles it uses three parabola segments. More precisely the parbelos consists of three parabola segments, that have a height t
Toroid
In mathematics, a toroid is a surface of revolution with a hole in the middle. The axis of revolution passes through the hole and so does not intersect the surface. For example, when a rectangle is ro
Helicoid
The helicoid, also known as helical surface, after the plane and the catenoid, is the third minimal surface to be known.
Auxetics
Auxetics are structures or materials that have a negative Poisson's ratio. When stretched, they become thicker perpendicular to the applied force. This occurs due to their particular internal structur
Inverted bell
The inverted bell is a metaphorical name for geometric shape that resembles a bell upside-down.
Trilon
A trilon is a three-faceted prism-shaped object. A trilon can be made to rotate on an axle to show different text or images which may be applied to any of its three facets. Trilons have been used on g
Circumgon
In mathematics and particularly in elementary geometry, a circumgon is a geometric figure which circumscribes some circle, in the sense that it is the union of the outer edges of non-overlapping trian
List of solids derived from the sphere
Polycon
In geometry, a polycon is a kind of a developable roller. It is made of identical pieces of a cone whose apex angle equals the angle of an even sided regular polygon. In principle, there are infinitel
Wallis's conical edge
In geometry, Wallis's conical edge is a ruled surface given by the parametric equations where a, b and c are constants. Wallis's conical edge is also a kind of right conoid. It is named after the Engl
Oloid
An oloid is a three-dimensional curved geometric object that was discovered by Paul Schatz in 1929. It is the convex hull of a skeletal frame made by placing two linked congruent circles in perpendicu
Superformula
The superformula is a generalization of the superellipse and was proposed by Johan Gielis around 2000. Gielis suggested that the formula can be used to describe many complex shapes and curves that are
Hyperboloid structure
Hyperboloid structures are architectural structures designed using a hyperboloid in one sheet. Often these are tall structures, such as towers, where the hyperboloid geometry's structural strength is
Squircle
A squircle is a shape intermediate between a square and a circle. There are at least two definitions of "squircle" in use, the most common of which is based on the superellipse. The word "squircle" is
Pyramid (geometry)
In geometry, a pyramid (from Greek πυραμίς (pyramís)) is a polyhedron formed by connecting a polygonal base and a point, called the apex. Each base edge and apex form a triangle, called a lateral face
Glossary of shapes with metaphorical names
Many shapes have metaphorical names, i.e., their names are metaphors: these shapes are named after a most common object that has it. For example, "U-shape" is a shape that resembles the letter U, a be
Surface
A surface, as the term is most generally used, is the outermost or uppermost layer of a physical object or space. It is the portion or region of the object that can first be perceived by an observer u
Coinage shapes
Although the vast majority of coins are round, coins are made in a variety of other shapes, including squares, diamonds, hexagons, heptagons, octagons, decagons, and dodecagons. They have also been st
Hexafoil
The hexafoil is a design with six-fold dihedral symmetry composed from six vesica piscis lenses arranged radially around a central point, often shown enclosed in a circumference of another six lenses.
Obconic
In botany, an obconic is an inverted cone shape. The term is most frequently applied to certain fruit or hypanthium structures with the apical end attached to the stem; however, less frequently the us
Paraboloid
In geometry, a paraboloid is a quadric surface that has exactly one axis of symmetry and no center of symmetry. The term "paraboloid" is derived from parabola, which refers to a conic section that has
Right conoid
In geometry, a right conoid is a ruled surface generated by a family of straight lines that all intersect perpendicularly to a fixed straight line, called the axis of the right conoid. Using a Cartesi
Femisphere
The femisphere is a solid that has one single surface, two edges, and four vertices.
Slab (geometry)
In geometry, a slab is a region between two parallel lines in the Euclidean plane, or between two parallel planes or hyperplanes in higher dimensions.
Ungula
In solid geometry, an ungula is a region of a solid of revolution, cut off by a plane oblique to its base. A common instance is the spherical wedge. The term ungula refers to the hoof of a horse, an a
Periodic table of shapes
The periodic table of mathematical shapes is popular name given to a project to classify Fano varieties. The project was thought up by Professor Alessio Corti, from the Department of Mathematics at Im
Gore (segment)
A gore is a sector of a curved surface or the curved surface that lies between two close lines of longitude on a globe and may be flattened to a plane surface with little distortion. The term has been
Helix
A helix (/ˈhiːlɪks/) is a shape like a corkscrew or spiral staircase. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as th
Bird (mathematical artwork)
Bird, also known as A Bird in Flight refers to bird-like mathematical artworks that are introduced by mathematical equations. A group of these figures are created by combing through tens of thousands
List of self-intersecting polygons
Self-intersecting polygons, crossed polygons, or self-crossing polygons are polygons some of whose edges cross each other. They contrast with simple polygons, whose edges never cross. Some types of se
Squround
A squround is a container whose shape is between a square and a round tub. It resembles an oval but is sometimes closer to a rectangle with rounded corners. These allow the contents to be easily scoop
Sphericon
In solid geometry, the sphericon is a solid that has a continuous developable surface with two congruent, semi-circular edges, and four vertices that define a square. It is a member of a special famil
Medial axis
The medial axis of an object is the set of all points having more than one closest point on the object's boundary. Originally referred to as the topological skeleton, it was introduced in 1967 by Harr
Equable shape
A two-dimensional equable shape (or perfect shape) is one whose area is numerically equal to its perimeter. For example, a right angled triangle with sides 5, 12 and 13 has area and perimeter both hav
Developable roller
In geometry, a developable roller is a convex solid whose surface consists of a single continuous, developable face. While rolling on a plane, most developable rollers develop their entire surface so
Ruled surface
In geometry, a surface S is ruled (also called a scroll) if through every point of S there is a straight line that lies on S. Examples include the plane, the lateral surface of a cylinder or cone, a c
Spherical shell
In geometry, a spherical shell is a generalization of an annulus to three dimensions. It is the region of a ball between two concentric spheres of differing radii.
Tri-oval
A tri-oval is a shape which derives its name from the two other shapes it most resembles, a triangle and an oval. Rather than meeting at sharp, definable angles as the sides of a triangle do, in a tri
Annulus (mathematics)
In mathematics, an annulus (plural annuli or annuluses) is the region between two concentric circles. Informally, it is shaped like a ring or a hardware washer. The word "annulus" is borrowed from the
List of two-dimensional geometric shapes
This is a list of two-dimensional geometric shapes in Euclidean and other geometries. For mathematical objects in more dimensions, see list of mathematical shapes. For a broader scope, see list of sha
Catalan surface
In geometry, a Catalan surface, named after the Belgian mathematician Eugène Charles Catalan, is a ruled surface all of whose rulings are parallel to a fixed plane.
Balbis
In geometry, a balbis is a geometric shape that can be colloquially defined as a single (primary) line that is terminated by a (secondary) line at one endpoint and by a (secondary) line at the other e
Hemihelix
A hemihelix is a curved geometric shape consisting of a series of helices with alternating chirality, connected by a perversion at the reversals. The formation of hemihelices with periodic distributio
Hyperboloid
In geometry, a hyperboloid of revolution, sometimes called a circular hyperboloid, is the surface generated by rotating a hyperbola around one of its principal axes. A hyperboloid is the surface obtai
Isotropic helicoid
An isotropic helicoid is a shape that is helical, so it rotates as it moves through a fluid, and yet is isotropic, so that its rotation and drag are the same for all orientations of the particle. It w
Spidron
This article discusses the geometric figure; for the science-fiction character see Spidron (character). In geometry, a spidron is a continuous flat geometric figure composed entirely of triangles, whe
Surface of constant width
In geometry, a surface of constant width is a convex form whose width, measured by the distance between two opposite parallel planes touching its boundary, is the same regardless of the direction of t
Archimedean circle
In geometry, an Archimedean circle is any circle constructed from an arbelos that has the same radius as each of Archimedes' twin circles. If the arbelos is normed such that the diameter of its outer
Reuleaux tetrahedron
The Reuleaux tetrahedron is the intersection of four balls of radius s centered at the vertices of a regular tetrahedron with side length s. The spherical surface of the ball centered on each vertex p
Jack (geometry)
In geometry, a jack is a 3D cross shape consisting of three orthogonal ellipsoids. Sometimes four small spheres are added to the ends of two ellipsoids, to more closely resemble a playing piece from t
Biconcave disc
A biconcave disc — also referred to as a discocyte — is a geometric shape resembling an oblate spheroid with two concavities on the top and on the bottom. Biconcave discs appear in the study of cell b