(a) A first order reflection from the (111) planes of a cubic crystal was observed at a glancing angle 11.20 using CuK radiation. Calculate the length 7 10. of

(a) A first order reflection from the (111) planes of a cubic crystal was observed at a glancing angle 11.20 using CuK radiation. Calculate the length 7 10. of the side of unit cell. (Given Sin11.20=.19)