clear
//
//
//

//Variable declaration
x=15            //distance(cm)
d=0.005         //diameter(cm)
lamda=6000*10**-8     //wavelength(cm)

//Calculation
alpha=d/x               //angle(radian)
beta1=lamda/(2*alpha)    //fringe width(cm)

//Result
printf("\n fringe width is %0.3f  cm",beta1)