Your answer would be 64 in².
To find the surface area, you just need to find the area of each of the shapes shown and add them together.
We can find the area of one of the triangles by doing:
(base × height)/2
(6 × 4)/2 = 24/2 = 12
As there are 4 identical triangles, the area of all of them would be 12 × 4 = 48 in².
Now we need to find the area of the square in the middle, which would be 4 × 4 = 16 in².
Adding these together gives us 16 + 48 = 64 in²
I hope this helps!