clear
//
//
//

//Variable declaration
h=2
k=2
l=0                     //miller indices
a=450                   //length(nm)  

//Calculation
d220=a/sqrt(h**2+k**2+l**2)          //interplanar spacing(nm)

//Result
printf("\n interplanar spacing is %0.1f  nm",d220)
printf("\n answer given in the book is wrong")