Surface area is the area of the faces added together.
First lets find the area of one of the triangles.
Area of triangle is 1/2*base*hight
Area=1/2*2*3= 3
Area of ONE tringle is 3, and area of the FOUR tringles is 4*3 whihc is 12
Now lets find area of square
area of square is side*side
So, area is 2*2 which is 4
Now lets add area of triangles+area of square
12+4 which 16
Surface area is 16