You can find the surface area of this square pyramid by first finding the area of the square base, which is equivalent to multiplying the square's length and with together or squaring one of the sides of the square, as all of the sides of a square have the same length. Next, you may substitute the length and height of a triangle into the formula for the area of a triangle, which is the base times the height, divided by 2. After that, you multiply the area of one triangle by 4, as there are 4 triangles that you need to find the surface area of. Finally, you add the surface area of the 4 triangles and the square together, and you will have found the surface area of the figure. I hope this helps!