co 27 khoi lap phuong nho bang nhau duoc ghep thanh mot hinh lap phuong lon . nguoi ta son tat ca cac mat cua hinh lap phuong lon do .
a] co.... khoi hinh lap phuong nho duoc son 3 mat .
b]co...khoi lap phuong nho duoc son 2 mat .
c]co .... khoi lap phuong nho duoc sin 1 mat.
d]co ... khoi lap phuong nho khong duoc son mat nao .
GHI CA CACH GIAI NUA NHA . LAM ON , HELP ME