There are:
2 rectangles with length 11 and height 7
2 rectangles with length 11 and height 6
2 rectangles with length 6 and height 7
So, their areas will be (respectively):
[tex]2(11)(7) = 154m^2[/tex]
[tex]2(11)(6) = 132m^2[/tex]
[tex]2(7)(6) = 84m^2[/tex]
Add all of them up:
[tex]154+132+84 = 370 m^2[/tex]
So, your answer is C.