# two-dimensional figure

Definitions of two-dimensional figure
1

### n a two-dimensional shape

Synonyms:
plane figure
Types:
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a plane figure with rounded sides curving inward at the top and intersecting at the bottom; conventionally used on playing cards and valentines
polygon, polygonal shape
a closed plane figure bounded by straight sides
conic, conic section
(geometry) a curve generated by the intersection of a plane and a circular cone
oblong
a plane figure that deviates from a square or circle due to elongation
hemicycle, semicircle
a plane figure with the shape of half a circle
sector
a plane figure bounded by two radii and the included arc of a circle
star
a plane figure with 5 or more points; often used as an emblem
paraboloid
a surface having parabolic sections parallel to a single coordinate axis and elliptic sections perpendicular to that axis
ellipsoid
a surface whose plane sections are all ellipses or circles
tree, tree diagram
a figure that branches from a single root
isogon
an equiangular polygon
convex polygon
a polygon such that no side extended cuts any other side or vertex; it can be cut by a straight line in at most two points
concave polygon
a polygon such that there is a straight line that cuts it in four or more points
ellipse, oval
a closed plane curve resulting from the intersection of a circular cone and a plane cutting completely through it
a four-sided polygon
triangle, trigon, trilateral
a three-sided polygon
hexagram
a regular polygon formed by extending each of the sides of a regular hexagon to form two equilateral triangles
asterism
(mineralogy) a star-shaped figure with six rays that is seen in some crystal structures under reflected or transmitted light
pentacle, pentagram, pentangle
a star with 5 points; formed by 5 straight lines between the vertices of a pentagon and enclosing another pentagon
pentagon
a five-sided polygon
hexagon
a six-sided polygon
heptagon
a seven-sided polygon
octagon
an eight-sided polygon
nonagon
a nine-sided polygon
decagon
a polygon with 10 sides and 10 angles
undecagon
an eleven-sided polygon
dodecagon
a twelve-sided polygon
spherical polygon
a figure on the surface of a sphere bounded by arcs of 3 or more great circles
parabola
a plane curve formed by the intersection of a right circular cone and a plane parallel to an element of the curve
hyperbola
an open curve formed by a plane that cuts the base of a right circular cone