Search results
Results from the WOW.Com Content Network
A polyhedron which does not cross itself, such that all of the interior can be seen from one interior point, is an example of a star domain. The visible exterior portions of many self-intersecting star polyhedra form the boundaries of star domains, but despite their similar appearance, as abstract polyhedra these are different structures. For ...
For example, a nine-pointed polygon or enneagram is also known as a nonagram, using the ordinal nona from Latin. [citation needed] The -gram suffix derives from γραμμή (grammḗ), meaning a line. [3] The name star polygon reflects the resemblance of these shapes to the diffraction spikes of real stars.
In general, a heptagram is any self-intersecting heptagon (7-sided polygon). There are two regular heptagrams, labeled as {7/2} and {7/3}, with the second number representing the vertex interval step from a regular heptagon, {7/1}. This is the smallest star polygon that can be drawn in two forms, as irreducible fractions.
Enneagram, a nine-pointed star polygon; Decagram, a ten-pointed star polygon; Hendecagram, an eleven-pointed star polygon; Dodecagram, a twelve-pointed star polygon; Magic star, a star polygon in which numbers can be placed at each of the vertices and intersections, such that the four numbers on each line sum to the same "magic" constant
A star domain (equivalently, a star-convex or star-shaped set) is not necessarily convex in the ordinary sense. An annulus is not a star domain.. In geometry, a set in the Euclidean space is called a star domain (or star-convex set, star-shaped set [1] or radially convex set) if there exists an such that for all , the line segment from to lies in .
Some types of self-intersecting polygons are: the crossed quadrilateral, with four edges the antiparallelogram, a crossed quadrilateral with alternate edges of equal length the crossed rectangle, an antiparallelogram whose edges are two opposite sides and the two diagonals of a rectangle, hence having two edges parallel; Star polygons
Scientists have detected what appears to be an incredibly dense star behaving unlike anything else ever seen - and suspect it might be a type of exotic astrophysical object whose existence has ...
The Vertical-horizontal illusion is the tendency for observers to overestimate the length of a vertical line relative to a horizontal line of the same length. Vista paradox: Visual tilt effects: Wagon-wheel effect: White's illusion: Wundt illusion: The two red vertical lines are both straight, but they may look as if they are bowed inwards to ...