clear // //variable declaration PB=20.0 //Load at point B,KN PC=10.0 //Load at point C,KN thetaA=60.0 //angleBAC thetaD=30.0 //angleBDC AC=3.0 //length,m CD=3.0 //length,m AB=(AC+CD)*cos(thetaA*%pi/180) BD=(AC+CD)*cos(thetaD*%pi/180) //mistake in book //angleBCA=angleABC=theta theta=(180.0-thetaA)/(2.0) //Taking moment about A, we get RD=(PC*AC+PB*AC*cos(thetaA*%pi/180))/(AC+CD) RA=PC+PB-RD //Joint A //vertical & horizontal forces sum to zero FAB=RA/sin(thetaA*%pi/180) printf("\n FAB= %0.2f KN [Comp.]",FAB) FAC=FAB*cos(thetaA*%pi/180) printf("\n FAC= %0.2f KN [Tensile]",FAC) //Joint D //vertical & horizontal forces sum to zero FDB=RD/sin(thetaD*%pi/180) printf("\n FDB= %0.2f KN [Comp.]",FDB) FDC=FDB*cos(thetaD*%pi/180) printf("\n FDC= %0.2f KN [Tensile]",FDC) //Joint C //vertical & horizontal forces sum to zero FCB=PC/sin(theta*%pi/180) printf("\n FCB= %0.2f KN ",FCB) //CHECK FCB=(FDC-FAC)/cos(theta*%pi/180) printf("\n FCB= %0.2f KN Checked",FCB)