Question

12. The length and breadth of a rectangular object are 25.2 cm and 16.8 cm respectively and
have been measured to an accuracy of 0.1cm. Find the relative error and percentage error in
the area of the object.
​

Answer 1

Area=l×b

A

△A

=

l

△l

+

b

△b

=(

25.2

0.1

+

16.8

0.1

)=0.00992≈0.01

This is the relative error.

Percentage error =0.01×100=1%

Answer 2

Answer: relative error=0.01 percentage error=1%

Explanation:A=l*b

∆A/A= ∆l/l + ∆b/b

 =0.1/26.2 + 0.1/16.8 = 0.00992

 ~ 0.01 (relative error)

percentage error= 0.01*100= 1%

Hope it helps