polygon area = n * side length^2 / 4 * tan(180/n)
where "n" = number of sides
hexagon area = 6 * 10^2 / 4 * tan(180/6)
hexagon area = 600 / 4 * tan(30)
hexagon area = 600 / 4 * 0.57735
hexagon area = 259.8077422707 square centimeters
hexagon area = 259.8 square centimeters