Q. Illustrate Truss with K-bracing ?

In the arrangement of triangulated framework in truss structures, it's more economical to design longer members as ties whereas shorter ones as struts (For instance Pratt truss). As such, tension forces are taken up by longer steel members whose load carrying capacities are unrelated to their lengths. Though the compression forces are reacted by shorter members that possess higher buckling capabilities than longer steel members. 

For heavy loads on a truss structure, depth of the truss is intentionally made larger so as to increase bending resistance and to decrease deflection. With the increase in length of vertical struts, buckling can take place under vertical loads. Consequently K-truss is designed in such a way that vertical struts are supported by compression diagonals.