This is from Australian Maths 2013.
In a regular hexagon,the midpoints of the sides are joined to form he shaded regular hexagon.What fraction of the larger hexagon is shaded?
Since the larger hexagon can be divided into 6 triangles. Let the height of the triangle be $h$ and base be $b$.
Area of larger hexagon=6 triangles= $6(\frac 12)(bh)=3bh$
Then,I know that since the midpoints of the sides are used to form another hexagon,there are another 6 triangles within the shaded hexagon.However I don't know the height and base,so I can't find the area.