该井当作台来处理,就是求圆台的侧面积s=πl(R+r)=π√((R-r)²+h²)×(R+)=π√((3.2-0.7)²+3.3²)×(3.3+0.7)=π√(2.5²+3.3²)×4=π√(6.25+10.89).×4=π√17.14×4≈3.14×4.12×4=51.74m²,而红砖长为0.24m,宽为0.053m,s=0..13m²,红砖对圆台侧面贡献率大约在60%左右,所以需红砖为51.74/(0.13×60%)=664块