[ \sum F_x = 0 \quad \sum F_y = 0 \quad \sum M_z = 0 ]
Integral forms:
[ \fracKLr, \quad r = \sqrt\fracIA ] For a pin-jointed truss in equilibrium at each joint: structural analysis formulas pdf
[ \sum F_x = 0, \quad \sum F_y = 0 ]
Distribution factor at joint: [ DF = \frack_i\sum k ] Rectangle (width (b), height (h)): [ I = \fracb h^312, \quad A = bh ] [ \sum F_x = 0 \quad \sum F_y