The surface area of the figure is given by
In this case there are 5 squares blue , 2 green and 2 triangles.
top and bottom squares area are:
For the lateral faces, the area will be:
We have 3 lateral faces and the other two on the top and bottom of the square:
And now, we have 2 triangle and two squares in green.
The surface area is the sum of the green area+ blue area