Answer:
3.6 cm
Step-by-step explanation:
If point B lies on segment AC, then the segment sum theorem applies.
Application
AB +BC = AC . . . . . . . . . . the whole is the sum of the parts
4.7 cm + BC = 8.3 cm
BC = 3.6 cm . . . . . . . . . . . subtract 4.7 cm from both sides
