Students' questions are incomplete. After searching, it is estimated that it is the following question:

It is known that when Rt△ABC, ∠ C = 90, AD is the bisector, AD=8, AC=4 and 3, and the length of BC is found.

Solution:

As shown in the figure, cos ∠ CAD = AC/AD = 4 √ 3/8 = 3/2.

∴∠CAD=30

AD is the angular bisector.

∴∠BAC=2∠CAD=60

∴∠B=90 -60 =30

∫tan∠B = AC/BC = 4√3/BC =√3/3

∴BC= 12

For reference!