Prisim and angle of deviation problem

[buttterfly41]

Light of wavelength 700 nm is incident on the face of a fused quartz prism at an angle of 77.0° (with respect to the normal to the surface). The apex angle of the prism is 60.0°. n=1.459.

a) the angle of refraction at the first surface
(b) the angle of incidence at the second surface
(c) the angle of refraction at the second surface
(d) the angle between the incident and emerging rays

i understand the first three by using geometry and snells law.. answers fro a) 41.9, for b) 18.1, for c)27.0. But i do not understand how to obtain the answer for part d. I thought it was asking for the angle of deviation in essence i thought , which is abs(theata1 - theata2). but other than that guess i don't know where else to take it from.

Any help would be wonderful. thankyou.

 

[Kurdt]

Try drawing a diagram of the ray path and it will help you see how to get the angle.