解答(a)图:
刚片数m =2, 单铰数n=2，支座链杆数r =1
自由度w =3m -2n -r =3x2 -2x2 -1 =1
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解答(b)图：
刚片数m =4,
3个单铰， 1个三杆复铰计作2个单铰，单铰数n =3+2 =5
自由度w =3m -2n -r =3x4 -2x5 -0 =2
