d*sin(θ)=m*λ

sin(θ)≈tan(θ)=(x_i)/l

(d*(x_i))/l≈d*sin(θ)=m*λ

d=0.125⋅10

λ=650⋅10

l=71.0⋅10

m=1

(x_i)≈(l*m*λ)/d=((71⋅10)*(1)*(650⋅10))/(0.125⋅10)=3.69⋅10=0.369

θ=arctan((x_i)/l)=arctan((3.5⋅10)/(71.0⋅10))=0.28