1. The problem statement, all variables and given/known data I have to find "sinθ" and "d" in the diffraction equation. 2. Relevant equations The formula is n(lambda) = d(sinθ) I have the n, length, width, and hypotenuse. http://img81.imageshack.us/my.php?image=captureee1.jpg n=1, L=335 W=42.5 hyp=337.8 3. The attempt at a solution I forgot how to get the angle for sin. So i'm pretty much stuck.