The $60$ strain rosette is mounted on the bracket. The following readings are obtained for each gauge: $lo{n}_a=-100{10}^{-8},lo{n}_b=250{10}^{-6}$ and $lo{n}_c=150{10}^{-6}$ Determine $($a$)$ the principal strains and $($b$)$ the maximum in$-$plane shear strain and associated average normal strain. In each case show the deformed element due to these strains. $($ANS: avg $=100{10}^{-6},1=308{10}^{-6},2=-108{10}^{-6},8\mathrm{.}05CW)$