求阴影部分的面积(空白部分面积为80平方厘米)。'y7{(x7~1c,Y7u
'y7{(x7~1c,Y7u
算式:提示:Q2\6}.|'k(f.h-f8z2t8s+r7n*X;O'y7{(x7~1c,Y7u
=8^4F6}(V+s:Z.R.B'y7{(x7~1c,Y7u