ba con cho tui hoi mot teo,voi thep ban thi nen bo tri thep nhu nao trong 2 phuong an tui gui kem hinh duoi day,ban day 8cm.co dam chinh va dam phu.
con thep chiu momen am tren cac dam thi de bao nhieu thanh tren 1m dai.va de a 300 co hop ly khong.?
con thep chiu momen am tren cac dam thi de bao nhieu thanh tren 1m dai.va de a 300 co hop ly khong.?
Ghi chú