What's the equation for regular polygons with $N$ sides?
10224
Is there an equation to describe regular polygons?
115209
Elementary formula for permutations?
62518
How many rectangles or triangles.
140625
What is the area of a polygon with n equal length sides?
108579
How do I efficiently determine if a polygon is convex, non-convex or complex?
22840
The sum of the first $n$ squares is a square: a system of two Pell-type-equations
153005
Calculating polygon area within polygons in QGIS?
127431
What is the equation for a string fixed at both ends without simplifying assumptions?
18124
Merging small polygons with the biggest adjacent ones
41907
Triangulation of a simple polygon (elementary proof?)
35066
Nature and number of solutions to $xy=x+y$
110638
Polygon with balls as corners
1294
How can I determine whether a 2D Point is within a Polygon?
136054
If $a_1,a_2,a_3,...,a_n$ are the side lengths of $A_1A_2A_3...A_n$ convex polygon,then$\frac{a^2_1+a^2_2+a^2_3+....+a^2_{n-1}}{a^2_n}$ is
76611
Centre in N-sided polygon on circle
44070
Recurrence  for number of regions formed by diagonals of a convex polygon.
97574
Jordan form, number of blocks.