A small source of light at the bottom face of a rectangular a plane bisecting the lens. The lens has a refractive index of glass slab 2.25 cm thick is viewed from above. Rays of light 1.52. Using the equivalence of optical paths through the totally internally reflected at the top surface outline a circle center and edge of the lens, determine the thickness of the of 7.60 cm in diameter on the bottom surface. Determine lens at its center. the refractive index of the glass.