Regular polygon with $n$ sides , the number of triangles
136563
Number of triangles in a regular polygon
96686
Determine the area of a regular octagon with vertices on the unit circle
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
87821
Different Coloring of regular n-gon
11967
number of subsets of even and odd
114795
Closed form for the area of a convex cyclic n-gon, given the set of edge lengths
24146
Number of ways to partition a rectangle into n sub-rectangles
18482
Can the squares with side $1/n$ be packed into a $1 \times \zeta(2)$ rectangle?
142477
Closed-form expression for the number of $k$-permutations of length $n$. Duplicates allowed!
107964
Simple combinatorics problem.
101339
Area of a cyclic polygon maximum when it is a regular polygon
76611
Centre in N-sided polygon on circle
10910
How many edges does an undirected tree with $n$ nodes have?
35083
Creating a Grid on a polygon and find number of points in each grid
15700
How to calculate how many polygons I can put inside a polygon?
13265
Volume of an n-simplex
45027
number of primitive Pythagorean triangles whose hypotenuses do not exceed n?