Answer: 175 square cm
Work Shown:
Area of square = side*side = 7*7 = 49
Area of one triangle = (1/2)*base*height = (1/2)*7*9 = 31.5
Area of four triangles = 4*(area of one triangle) = 4*31.5 = 126
total area = (area of square)+(area of four triangles) = 49+126 = 175
This total area of the net is the same as the surface area of the square prism. Imagine folding this 2D flat shape to form a 3D figure.