P$13\mathrm{.}3$ The thin rectangular plate shown in Figure P$13\mathrm{.}3/4$ is uniformly deformed such that ${}_x=120,{}_y=-860,$ and ${}_{xy}=1,100rad.$ If $a=25mm,$ determine

$($a$)$ the normal strain ${}_n$ in the plate.

$($b$)$ the normal strain ${}_t$ in the plate.

$($c$)$ the shear strain ${}_{nt}$ in the plate.