//ch-1  page -38  pb-2

//

//

ab=550
AB=ab*(cos(15*(%pi/180)))

l=20
e=0.05
l1=l+e
ml=AB
printf("\n measured length is  %0.3f meters',ml)

tl=(l1/l)*ml

printf("\n true length is  %0.3f meters',tl)