Each quadrant is a sector of 90° in a circle of 1 cm radius.

Area of each quadrant

Area of square = (Side)^{2} = (4)^{2} = 16 cm^{2}

Area of circle = πr^{2} = π (1)^{2 }=22/7 cm^{2}

Area of the shaded region = Area of square − Area of circle − 4 × Area of quadrant