help

The area of a regular hexagon A is related to its length L by 

$A = \dfrac{3\sqrt 3}2 L^2$

Consider the top white isosceles triangle.

The base is $2L\sin 60^\circ = \sqrt 3 L$. This is also the length of the rectangle.

The width of the rectangle is $L$, so the area of the rectangle is $\sqrt 3 L^2 = \dfrac23 A$.

The area of rectangle is two thirds of the area of the hexagon, which is 60.