Hard
The figure shows a regular hexagon and a shaded triangle got by extending the sides. If the area of the regular hexagon is 36 sq. units then the area of the shaded triangle is:
Extending two adjacent sides of a regular hexagon forms an equilateral triangle whose area is 1/6th of the hexagon's area (since a regular hexagon comprises 6 equilateral triangles of that same size). So area = 36/6 = 6 sq. units.
Re-check your working by substituting the answer back into the original question.