Since this is a regular hexagon with internal angle = 120 degrees we can split this up to 6 equilateral triangles. And as each triangle = twice a 90-60-30 triangle if the height is 5sqrt3 the base will be 2*5 = 10 cms.
Therefore the area of the hexagon = 6 * 1/2 * 5sqrt3 * 10 = 150sqrt3 cm^2
