1. The problem statement, all variables and given/known data fringes are observed when a parrallel beam of light of wavelength 500nm is incident perpendiculary onto a wedge-shaped film with an index of refraction of 1.5. What is the angle of the wedge if the fringe separation is 1/3cm? 2. Relevant equations t(x)=xtan(theta) 2nt=m*lamda (m+.5) for deconstructive x=(lamda/2)/2n*tan(theta) t=lamda/2n 3. The attempt at a solution ok im really struggling to understand this qn, i thought simple trig, t=1.66x10^-9 but now completely stuck... coz i think i need the x value..... but no idea how to find it??? can anyone help?