Question 14
In an equilateral triangle of side length a, the distance h from the centre of the triangle to any side satisfies $a^2=12h^2$ . Lily uses four equilateral triangles of side length 6 cm to make a cardboard windmill with three blades. Two triangles sharing a common vertex have the corresponding sides lying on the same straight line, as shown in the diagram. Taking $\pi\approx3.14$ , what is the area, in cm² , of the circle swept out by the blades of the windmill?
