tolong yang no.11 ya!

diketahui = panjang AB =(bd+ba) 9 cm
= panjang AD = 5 C

ditanya = panjang BC = ...?

dijawab =
[tex]bc = \sqrt{bd \times ba} \\ = \sqrt{4 \times (4 + 5)} \\ = \sqrt{4 \times 9} \\ = \sqrt{36 } \\ = \sqrt{4} \sqrt{9} \\ = 2 \times 3 \\ = 6[/tex]