“nba88009”：您好.割成长方体后,增加了八个面,每个面的面积为：50.24dm²÷8=6.28dm²每个面的宽为√(4²+4²)dm=√32dm=4√2dm原圆柱高为:6.28dm²÷4√2≈6.28dm²÷5.66dm≈1.11dm此圆...