What Happens to the Refraction Angle as the Incident Angle Nears 90 Degrees?

[ohlhauc1]

I have a question concerning this question:

Predict what will happen as the incident angle approaches 90 degress, and develop a method to test the prediction.

I say the refraction angle would also be 90 degrees (remaining a horizontal line), so my method would be to align the laser I'm using to the 90 degree mark and shine it so that just enough of it passes through the medium.

Is that correct and if not, any suggestions?

 

[ohlhauc1]

I would also put a barrier to help align the laser.