B$2(15$ pts$,$ Text $6\mathrm{.}6,$ modified$)$: In the triangular element shown in the Figure, assume nodal coordinates to be: node $1(1,1),$ node $2(12,6),$ node $3(3,8).$ Obtain the strain$-$displacement relation matrix $B$ and determine the strains ${}_x,{}_y$ and ${}_{xy}.$ Find stresses, assuming that $q$ and $x$ are given in $cm,E=10$GPa, $v=0\mathrm{.}2$ for plane strain problem.

$-{}_{n01},n_{-}=-0\mathrm{.}004$