Contradicting passage explanation? TBR. Help needed

[SonhosDaVida]

So the answer key is saying that a refracted angle will Be 0 degrees of the incident angle is 90 degrees to the boundary (in pink).

But (in green), TBR is saying that from air, if a light wave hits flint glass at 90 degrees, then the refracted angle will be 38.1 degrees.

Isn’t this contradicting what it said above?

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[AdaptPrep]

Hi, SonhosDaVida--

The passage says that if the incident ray is 38.1 degrees, the refracted ray is 90. Then, it says reverse the situation. HOWEVER, note what they added in the following sentence (after the green highlight), if the incident ray is "just slightly less than 90 degrees" the refracted ray will be slightly less than 38.1. They cannot use exactly 90 degrees for the reason stated earlier. They are being consistent, but the wording can be confusing at first if you miss the words "slightly less".