Given, the circle is inscribed in a square,

So, the diameter of the circle must be equal to the side of the square

Now, diameter d = 28 cm

radius r = d/2 = 28/2 = 14 cm

Now, area of the circle = πr²

                                  = π(14)²

                                  = (22/7) * 14 * 14

                                  = 22*2*14

                                  = 616

So, the area of the circle = 616 cm²