On the periphery of a square grass field ABCD, two poles are fixed. One is at the mid point of AB and another at mid point of BC. Side of the square ABCD is 16m. a cow is tied to one pole and another is tied to the other pole. if each cow is tied with 8m long rope, then find the area of the field unreachable to the cows. in sq m

1) 256-32(pi)
2) 216-32pi
3) 192-32pi
4) 240-32pi