In the figure, light is incident at angle θ1 = 37∘ on a boundary between two transparent materials. Some of the light travels down through the next three layers of transparent materials, while some of it reflects upward and then escapes into the air. If n1 = 1.28 n2 = 1.42, n3 = 1.34 and n4 = 1.47, what is the value of (a)θ5 and (b)θ4? (a) θ5 = Number i Units (b) θ4 = Number Units