Can anyone please help me out with this problem

Problem Statement

You are given a int length . We have a regular hexagon: a polygon with six sides, in which all internal angles have 120 degrees and length is the length of each side. We are going to draw three non-intersecting diagonals in some way. These will divide the hexagon into four triangles. We will then compute their areas, take a piece of paper and write down the smallest of those four areas. Compute and return the largest number we can obtain on our piece of paper (by choosing which diagonals to draw).

Examples
5
Returns: 10.825317547305485

10
Returns: 43.30127018922194

100000
Returns: 4.330127018922194E9

It’s a real math problem. Make sure you get the formula or you should flip through your elementary school textbook.