Returns the convex hull of the specified points using Andrew’s monotone chain algorithm.
The returned hull is represented as an array containing a subset of the input points arranged in
counterclockwise order. Returns null if points has fewer than three elements.
Parameters
points: Array<[number, number]>
Array of coordinates , and so on.
Returns Array<[number, number]> | null
polygonLength
polygonLength(polygon: Array<[number, number]>): number
Returns the length of the perimeter of the specified polygon.
Returns the signed area of the specified polygon. If the vertices of the polygon are in counterclockwise order ( assuming a coordinate system where the origin ⟨0,0⟩ is in the top-left corner), the returned area is positive; otherwise it is negative, or zero.