??????????????????1?ê?
????ía???o(3¤+?í+8)/100 x(?í+??+6)/100 x ????(?a/CM2)
?????DoD?o{(3¤+?í)*2+4}/100x{(?í+??)*2)}/100* ????(?a/CM2)
????ía???o(3¤+?í+7)/100 x(?í+??+3)/100 x ????(?a/CM2)
?????ú???o(3¤+?í+7)/100 x(?í+??+3)/100 x ????(?a/CM2)
???????D??3¤?í?????????aCM??????òa?'??2??êà'?¨??????
????2êoD??????????1?ê?
????2êoD???1?a???y( M2 ) X ??êy( 3.8 ~ 4 )??è?1??'?¤???ò??êy?a4.8 ??
?????1?a???y??????·?·¨?o?2( 3¤ + ?í ) X 2 + 3 ?3/100 X ?2( ?í X 2 + ?? ) + 2 ?3/100 ???D3¤???í?????aCM??
????àyè?ò???2??'?¤2êoD??3?'??a 7 X 6 X 16 CM
?????ò?1?a???y?a?2( 7 + 6 ) X 2 + 3 ?3/100 X ?2( 6 X 2 + 16 ) + 2 ?3/100 = 0.087 M2 ?ò2êoD'ó???????a 0.087 X 4 = 0.35?a ×??o??1à??·?·¨???üó?óú3?'???D???2êoD??
????ò?°?í?à?2êoD???ù±?3é±??÷òa°üà¨?oó???3é±???í?à?3é±???ó???·?ó???é?ó????11a???'?¤??3é±????3ìù1¤×êoí?°ê??è??
????????1???ò?°?óDá???:±ê1?78.7 X 109 CM oí 'ó1?89 X 119 CM .
????2êoD??????????·?·¨?a°'2êoD??ê??ê?1?a3?'????ù?Y±ê1?(?ò'ó1?)3?'?????3??ù?ü×???oD×ó??êy??'ó????3?????oD×óó?????·?ó????ù?óé?í?à???ó?????é?ó????11a???'?¤?°?°ê??è·?ó???
????ò?°?????2êoD3é±?Dèáí?ó??°?·??°????·?????í¨3?'???°?·??a300~ 600?a??????·??a 150?a??
