mot san truong hinh chu nhat co chu vi la 120 m nay nha truong mo rong them ve phia chieu dai 1 doan bang 1/2 chieu dai san truong cu nen chu vi san truong mmoi la 156 . San truong duoc lat gach hinh vuong co canh 2 dm . Hoi san truong do lat het bao nhieu vien gach ? biet cac vien gach vua cheu 6 m vuong
vu may dep dep lam hay sao ma khoe chu ^ ^