There is a three-Legged
stool and a four-legged stool. Suppose that each stool is placed on a flat surface that is slightly sloped do you expect either of the stool to rock from side to side? Explain why or why not
the 4 legged stool will rock. the 4 ends of the legs form a plane. they cannot sit on an uneven surface. the area they sit on must be planar. the 3 legged stool, however, can sit without rocking, because any 3 points define a plane entirely
