s=abc=2（a+b）s=ab=4.06*8=32.48c=2（a+b）=2*（4.06+8）=24.12
S=ab=4.06*8=32.48平方厘米C=2ab=2*(4.06+8)=24.12厘米
s=ab=32.48c=2(a+b)=24.12
