Just solve c d and e ASAP please

1t). Light traveling in a vacuum with a wavelength at T1nrn enters a plexiglass window on the space station at an angle cf 55". The index at refraction for plexiglass is 1.5[1 K1315] a} What is the frequency cf this light it a vacuum? b} What is the frequencyr cf this light it the plexiglass? c} What is the speed of the light in plexiglass? {I} What is the wavelength at the light in plexiglass? e} What is angle at retraction at the tight in ptexiglass