Optic question about a positive-meniscus lens

[mrquanta]

i was asked to find the angle $$\theta$$, the height h₂, and the back focal length in terms of the radius of curvatures. I'm really stunned that i couldn't draw a line. thanks in advance.

http://img94.imageshack.us/img94/8336/lens.png

 

[gabbagabbahey]

Hi mrquanta, welcome to PF!

You must show some attempt at a solution to receive help. We are not here to do your homework for you.

Why not start by calculating the angle of incidence (in terms of $h_1$ and $R_2$, via basic geometry) of the oncoming ray on the leftmost surface?...What does knowing that angle of incidence allow you to calculate (via Snell's Law)?