www.intmath.com/blog/mathematics/calculating-polygon-angles-and-sides-lengths-12474

Sep 23, 2020 ... Polygons must have at least three sides as a two-sided shape cannot be closed. The point where two sides meet is called a "vertex" (plural: ...

www.mathplanet.com/education/geometry/points,-lines,-planes-and-angles/polygons

Polygons. A polygon is a closed figure where the sides are all line segments. Each side must intersect exactly two others sides but only at their endpoints ...

www.shapeways.com/forum/t/new-2-sided-and-3-sided-dice.54574

Sep 18, 2016 ... By removing 4 or 3 edges on a cube you can obtain a 2-sided or 3-sided shape with non planar sides. These shapes are not new at all.

tutors.com/math-tutors/geometry-help/parallel-sides

The parallelogram is a special type of quadrilateral. It is named for its property of having two pairs of parallel sides (left and right, top and bottom) but no other ...

www.web-formulas.com/Math_Formulas/Geometry_Perimeter_of_Polygon.aspx

4-sided polygon with two pairs of parallel sides. Pentagon. 5-sided polygon ...

www.storyofmathematics.com/polygons-definition

A polygon is a closed 2D figure made up of line segments but not curves. ... Kite: Two pairs of adjacent sides are of equal length; the shape has an axis of ...

www.nuffieldfoundation.org/sites/default/files/files/FSMQ%20What%20am%20I.pdf

I have 2 pairs of parallel, equal sides, but my sides are not all equal. I have no right angles. What am I? I am a parallelogram. I am a 2D shape. I have 3 sides.

www.nde-ed.org/EducationResources/Math/Math-Geometry.htm

One dimensional shapes are called lines and two dimensional shapes are flat shapes like circles ... The sum of the angles in a polygon of n sides is 180º x (n-2) .

www.math-salamanders.com/list-of-geometric-shapes.html

Rectangle. list of geometric shapes rectangle. Rectangles have 4 sides and 4 right angles. They all have 2 lines of symmetry (4 lines if they are also a square!)

bookbuilder.cast.org/view_print.php?book=38142

A quadrilateral is a closed figure with 4 sides. Some shapes that are classified as quadrilaterals are square, rectangle, parallelogram, rhombus, and trapezoid.