A double-slit interference pattern has fringes that are 8.8 mm apart. The region over which you can see bright fringes is 11 cm wide. The fringes will still be 8.8 mm apart, but the size of the region before they fade out becomes smaller than 11 cm. The region of bright fringes will still be 11 cm, but the distance between the fringes becomes less than 8.8 mm. Two panes of glass are stacked on top of one another with a thin layer of air between them.
Light is incident from above.