2、40×12÷8=60(厘米)
?????????????
?????????Σ?????????С?1???2???????1:3????2???3????????3:2?????????????????????????????Σ?
?????????????д??9600???????????????????????40%???????????????120???????????????????????????????????
?????????????
?????????Σ?????????С?1???2???????1:3????2???3????????3:2?????????????????????????????Σ?
?????????????д??9600???????????????????????40%???????????????120???????????????????????????????????