b$)$ What is the arca of a rectangular field and its estimated error for the following, recorded values:

$243\mathrm{.}89+-0\mathrm{.}05ft,by208\mathrm{.}65+-0\mathrm{.}04ft.(3$Marks$)$

$725\mathrm{.}33+-0\mathrm{.}08ftby664\mathrm{.}21+-0\mathrm{.}06ft.(3$Marks$)$

$128\mathrm{.}526+-0\mathrm{.}005m,by180\mathrm{.}403+-0\mathrm{.}007m.(4$Marks$)$