The critical angle for a typical glass air interface is $42^\circ$. If a ray of light falls normally on one of the faces of the prism of angle $45^\circ$, the emergent ray will:
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Whenever light hits a surface normally ($i = 0^\circ$), it goes completely straight without bending. At the next surface inside a prism, your angle of incidence is always equal to the prism's vertex angle ($i = A$) if the first surface was normal!