For the given crystal, it is possible to obtain experimentally the glancing angles for the maxima of reflected X-rays respectively using three different reflecting planes.

For example, In case of KCL crystal, Bragg obtained the first order of maximum of reflected X-rays at glancing angles 5.22 degrees, 7.30 degrees and 9.05 degrees respectively using three different reflecting planes.

From Bragg’s equation 2d sin(theta) = n Lamda
So, for first order spectrum 2d sin(theta) = Lamda
i.e. 1/d = 2 sin (theta) / Lamda
Thus, knowing the values of theta for reflections from different reflecting planes in given crystal and lamda, it is possible to find the ratio 1/d₁₀₀ : 1/d₁₁₀ : 1/d₁₁₁and from this ratio, it is possible to analyse the given crystal structure.

For example for KCL crystal,
           1/d₁ : 1/d₂ : 1/d₃ :: sin 5.22 : sin 7.30 : sin 9.05
i.e.      1/d₁ : 1/d₂ : 1/d₃ :: 0.091 : 0.127 : 0.157
i.e.      1/d₁ : 1/d₂ : 1/d₃ :: 1: 1.4 : 1.73

This result shows that KCL is simple cubic crystal.

In this way Bragg’s law is useful in the analysis of the crystal structures.