Ve mot tam giac ABC, biet ba canh BC = 4cm, AB = 3cm. AC =2cm.
-Ve doan thang BC = 4cm.
-Ve cung tron tam B, ban kinh 3cm.
-Ve cung tron tam C, ban kinh 2cm.
-Lay mot giao diem cua hai cung tren, goi giao diem do la A.
-Ve doan thang AB,AC, ta co ABC