cac ban giup mik giai bai nay voi a
Ve doan thang AB dai 7cm . Lay diem C nam giua A,B sao cko AC=3 cm
a) Tinh do dai doan thang CB
b) ve trung diem I cua doan thang AC. tinh IA, IC
c) tren tia doi cua tia CB lay diem D sao cko CD=7 cm. So sanh CB va DA?
bai nay mik ko co dau nen cac ban thog cam