Lami's theorem. (mechanics). When three forces act on a particle in equilibrium, the magnitude of each is proportional to the sine of the angle between the other two. 1  Facebook.
Variable reactions: Brown recluse spider's bite can cause no reaction, a mild reaction, an immediate or a delayed reaction. With a significant reaction a which blister appears after bit. The surrounding skin becomes hard, swollen & can be red, white & blue. A deep lesion can develop which can eat through fat and muscle.
1 Other symptoms include fever, chills, nausea, vomiting, muscle aches and hemolytic anemia (a condition where the red blood cells are destroyed).  People bitten by an unseen spider sometimes blame the brown recluse spider because their bite resembles a brown recluse spider bite.