Solving a problem in physics section 2 point 5 optics

Solving a problem in physics section 2 point 5 optics

5. On the way of the light wave propagating in the air, put a glass plate having a thickness h = 1 mm. How much change the optical path length ?L, if the wave incident on the record: 1) normal; 2) at an angle ? = 30°?

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Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)