Split the trapezium into a rectangle and a triangle and work out the areas of them.
4x6=24
(2x4)/2=4
Area of trapezium= 28
There are 2 trapeziums, which makes 56.
The back of the shape is 4x14=56.
The top of the shape is 6x14=84.
The underside of the shape is 8x14=112.
The front rectangle is 14x4.47= 62.58.
As them all together= 56+56+84+112+62.58=370.58.
Total surface area=370.58.
Hope this helps :)