Please answer the problem below, Nscp $2015,$ Asap. thank you very much

$1.$ A double angle truss member CD and BD consist of two angle $102$ x $76$ x $7\mathrm{.}9$ mm thick with $102$ mm side welded to a gussetplate.. Using E$70$ electrode, determine the length of each weld required in member CD and BD$.$ Use Fy $=250$ MPa and ybar $=31\mathrm{.}8$ mm and size of weld $=6$ mm$.$ Use ASDL$2$L$100$ KN$10$ m$200$ KNBC$10$ m$200$ KNE$10$ m$100$ KN