Answer:
384mm
Explanation:
The surface area of a square pyramid is 1/2 the product of its base perimeter & slant height.
SA = area of base + 1/2 (perimeter of base * slant height)
So, we can substitute 12 and 10 into this equation.
The area of the base is 12*12 (144). The perimeter of the base is 48mm.
144 + 1/2(48*10) = Surface Area.
144 + 240 = Surface Area.
384mm = Surface Area.
Hope that helps :)