Question: how to find hkl values?
Answer: A. ...  Recognize the hkl values for the first few peaks: 100, 110, 111, 200, 210, 211, 220, etc. Calculate the interplanar spacing, d, for each peak: 1/d2 = (h2 + k2 + l2)/a2. ...  Use Bragg's Law to determine the 2θ value: λ = 2d.