Q$3$ A rigid beam is supported at the three pins, A$,$ B$,$ and C by the wall and the two elastic members

of common material and identical cross$-$section. The rigid beam is weightless but carries an end

load $W.$ Find the forces in the members $BD$ and $CD$ in terms of $W.$ load $W=5$ kips, $L=12ft,$

areas of cross sections for members $AB,BD$ and $CD$ are $12i{n}^2,$ and $2i{n}^2$ respectively, $EI=29x$

${10}^3$ksi.