tolong jawab pake cara yaa..makasih

CB = AD
CB = AD triple phytagoras 6 dan 10 = 8cm
perbandingan 9/6 = 3/2

3 / 2 = 8 / ( 8 - FD )

= 3 ( 8 - FA ) = 2 . 8
= 24 - 3 FA = 16
= - 3 FA = 16 - 24
= - 3 FA = - 8
FA = - 8 / - 3
FA = 2,6 cm
FD = AD - FA
FD = 8 - 2,6
FD = 5,4 cm