a regular hexagon is like 6 isosceles triangles squashed together, with a 60 degree angle in the center of the hexagon.
in this problem each of those triangles have two sides of length 4
area of an isosceles triangle (when we know the inside angle and the 2 sides) is:
A = (1/2) * side^2 * sin(angle)
A = 0.5 * 4^2 * sin(60)
A = 0.5 * 16 * sqrt(3)/2
A = 4 * sqrt(3), in square centimeters
but we have 6 triangles to make the hexagon, so
Answer = 24 * sqrt(3),in square centimeters