Question

[nguyen thi phuong hang]

Mot hinh thang vuong co day be=3/5 day lon va co chieu cao =23cm .Nguoi ta mo rong hinh thang bang cha keo dai day be cho bang day lon de duoc mot hinh chu nhat, sau khi mo rong dien tich hinh thang tang them 207cm .Tim dien tich hinh thang luc chua mo rong?