According to the question, Length of the rectangle, l=1m and breadth, b=50cm=0.5m ∴ Area of rectangle, A=l×b ‌∴‌ln‌A‌‌=ln‌l+ln‌b ⇒‌‌
δA
A
‌‌=‌
δl
l
+‌
δb
b
Here, ‌
δl
l
=‌
δb
b
=1%=0.01 ∴‌‌δA‌‌=A(‌
δl
l
+‌
δb
b
)‌‌[∵A=l×b=1×0.5] ‌‌=1×0.5(0.01+0.01)=0.01 Area of the table including error is A′=A±δA ⇒‌‌A′=(0.5±0.01)m2