please I need help with these questions:

1. A slab of glass has a 0.700 cm thick layer of water on top of it. A light ray strikes the water from air at an incident angle of 50.0. At what angle does the light ray travel through the glass?

Angle:

2. At what angle ? does the laser beam need to be at to hit the mirror then hit the midpoint of the wall? The height of the room is h = 3.20m and the width of the room is w = 5.70 m.

Mirror h Wall Laser beam W