## Plane Geometry

Plane geometry is a two dimensional figure, also called planar geometry, with edges.  The edges are line segments or edges and curve segments or arcs, all lying on a flat plane.

## Plane Geometry Types

• Circle  -   All points are at a fixed equal distance from a center point.  See [ 1 ]
• 3 Overlapping Circle  -  Equal length arcs connecting at the vertices of three overlapping circles.
• 3 Connecting Circle  -  Three equal length arcs connecting at the vertices bound by circles.
• 4 Connecting Circle  -  Four equal length arcs connecting at the vertices bound by circles.
• Circle Corner  -  A right triangle having acute vertices on a circle with the hypotenuse outside the circle.
• Circle Sector  -  A part of the interior of a circle having two radius boundries and an arc.
• Circle Segment  -  An interior part of a circle bound by a chord and an arc.  See [ 1 ]
• Half Circle  -  Half of the interior of a circle having a straight chord and an arc.  See [ 1 ]
• Hollow Circle  -  Two circles each having all points on each circle at a fixed equal distance from a center point.  See [ 1 ]
• Quarter Circle  -  A part of the interior of a circle having two radius boundries at a 90° angle and an arc.  See [ 1 ]
• Thin Wall Circle  -  Two circles each having all points on each circle at a fixed equal distance from a center point.  See [ 1 ]
• Ellipse  -  A two-dimensional figure with a conic section or a stretched circle.
• Ellipse Sector  -  A part of the interior of an ellipse having two radius boundries and an arc.
• Ellipse Segment  -  An interior part of a ellipse bound by a chord and an ellipse.
• Hollow Ellipse  -  Two ellipses with a conic section or a stretched circle.
• Polygon  -  A closed plane figure for which all edges are line segments and not necessarly congruent.
• Concave Polygon  -  A polygon where one or more angles are greater than 180° and some vertices point inward.
• Convex Polygon  -  A a polygon where all interior angles are less than 180° and all vertices point outward.
• Irregular Polygon  -  A polygon where all edge and angles are not the same.  It can be concave or convex.
• Regular Polygon  -  A polygon where all edges are congruent and all angles are congruent.
• Self-intersecting Polygon  -  A polygon where one or more edges cross over another.
• Triangle  -  A polygon with 3 edges.
• Quadrilateral  -  A polygon with 4 edge.
• Acute Trapezoid  -  A trapezoid has two adjacent acute angles on its longer base edge.
• Isosceles Trapezoid  -  A trapezoid with only one pair of parallel edges and having base angles that are the same.
• Kite  -  A quadrilateral with two pairs of adjacent edges that are congruent.
• Obtuse Trapezoid  -  A trapezoid with one acute and one obtuce angle on each base.
• Parallelogram  -  A quadrilateral with two pairs of parallel opposite edges.
• Rectangle  -  A quadrilateral with two pair of parallel edges.  See [ 1 ]
• Rhombus  -  A parallelogram with four congruent edges.
• Right Trapezoid  -  A trapezoid with only one pair of parallel edges and two adjacent right angles.
• Rounded Corner Rectangle  -  A quadrilateral with two pair of parallel edges and rounded corners.
• Self-intersecting Rectangle  -  One edge crosses over another.
• Square  -  A quadrilateral with four equal edge lengths and 90° interior angles.  See [ 1 ]
• Trapezoid  -  A quadrilateral that has a pair of parallel opposite edges.
• Tri-equilateral Trapezoid  -  A trapezoid with only one pair of parallel edges and having base angles that are the same with three congruent edges.
• Pentagon  -  A polygon with 5 edges.
• Hexagon  -  A polygon with 6 edges.
• Heptagon  -  A polygon with 7 edges.
• Octagon  -  A polygon with 8 edges.
• Nonagon  -  A polygon with 9 edges.
• Decagon  -  A polygon with 10 edges.
• Hendecagon  -  A polygon with 11 edges.
• Dodecagon  -  A polygon with 12 edges.
• Triskaidecagon  -  A polygon with 13 edges.
• Tetrakaidecagon  -  A polygon with 14 edges.
• Pentadecagon  -  A polygon with 15 edges.
• Hexakaidecagon  -  A polygon with 16 edges.
• Heptadecagon  -  A polygon with 17 edges.
• Octakaidecagon  -  A polygon with 18 edges.
• Enneadecagon  -  A polygon with 19 edges.
• Icosagon  -  A polygon with 20 edges.
• Triacontagon  -  A polygon with 30 edges.
• Tetracontagon  -  A polygon with 40 edges.
• Pentacontagon  -  A polygon with 50 edges.
• Hexacontagon  -  A polygon with 60 edges.
• Heptacontagon  -  A polygon with 70 edges.
• Octacontagon  -  A polygon with 80 edges.
• Enneacontagon  -  A polygon with 90 edges.
• Hectogon  -  A polygon with 100 edges.
• Chiliagon  -  A polygon with 1,000 edges.
• Myriagon  -  A polygon with 10,000 edges.

Display #
Title
Circle Segment
Circumference of a Circle
Concave Polygon
Convex Polygon
Cross
Diameter of a Circle
Ellipse
Ellipse Sector
Ellipse Segment
Equilateral Triangle