The hexagon is made up of two trapezoids, each having the following dimensions:
[tex]a=12\text{ m}\\b=5\text{ m}\\h=4\text{ m}[/tex]
So, its total area is the sum of the areas of those two trapezoids.
[tex]A_h=2A_t=2\cdot\dfrac{1}{2}(a+b)h=(a+b)h\\A_h=(12+5)\cdot 4=68\text{ m}^2[/tex]
