BAI1/Cho hinh thang ABCD co day nho AB bang 10,8 m day lon DC bang 27 m noi A va C . Tinh dien tich tam giac ABC la 54m2
bai2/ Trung binh cong cua ba so la 91 tom ba so do biet so thu nhat gap doi so thu hai va so thu hai kem so thu ba 13 don vi
bai3/ Cho hinh thang ABCD co day lon CD la 20m day be =15m M la diem tren AB cach B la 5m noi M voi C Tinh dien tich hinh thangAMCD biet dien tich hinh tam giac MBC la 28 m2