If L = 20.04 m `pm`0.01 m , B= 2.52 m `pm ` 0.02 m . What are the values of `(L xx B) and (L+B)` ?

Explanation

Given errors are absolute errors, while the rule says that percentage errors are to be added. Hence, the first step will be to convert the given absolute errors into percentage errors.
`L= 20.04 m +- (0.01)/(20.04) xx 100% = 20.04m +- 0.05%`
`B= 2.52m +- (0.02)/(2.52) xx 100% = 2.52 m +- 0.79%`
`L xx B= (20.04 xx 2.52)m^(2) +- (0.05 + 0.79)%`
`=50.50m^(2) +- 0.84%`
This is the result. However, since the data given in the question was in terms of absolute errors, so we should give our result also in absolute errors.
`L xx B= 50.50 m^(2) +- (0.84)/(100) xx 50.50m^(2)`
`=50.50 m^(2) +- 0.42 m^(2)`