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Alphabetical Index
New in MathWorld
Octagon
An octagon is an 8-sided polygon.
Octagon is an elementary-school-level concept.
Classroom Articles on Polygons
Decagon
Pentagon
Dodecagon
Polygon
Equilateral Triangle
Quadrilateral
Hendecagon
Rectangle
Heptagon
Regular Polygon
Hexagon
Right Triangle
Isosceles Triangle
Square
Nonagon
Trapezoid
Parallelogram
Triangle
Classroom Articles on Geometry (Up to Elementary-School Level)
Acute Angle
Parallel
Angle
Perimeter
Area
Perpendicular
Circle
Point
Cone
Prism
Cube
Pyramid
Cylinder
Radius
Diameter
Sphere
Geometric Construction
Surface Area
Obtuse Angle
Volume