120*(120-3)/2 = 7020
Chat with our AI personalities
A normal convex polygon cannot have 15 diagonals. If it has n sides, it has n*(n-3)/2 diagonals and this is equal to 15 if n = 7.18. However, it is not possible for a polygon to have a fractional side.
It works out that a polygon with 1175 diagonals has 50 sides
1/2*(142-42) = 77 diagonals
It depends if the polygon is convex or concave but if it is a regular polygon it would have 560
The formula for the number of diagonals is: 0.5*(n^2-3n) whereas 'n' is the number of sides of the polygon