Answer:
BD = 4.1
Explanation:
DA is an angle bisector which also divides the opposite side of the angle it bisects in a way that it is proportional to tye other two sides.
By implication, we would have the following:
AB/BD = AC/DC
AB = 5.3
AC = 5.5
DC = 4.3
BD = ?
Plug in the values
5.3/BD = 5.5/4.3
Cross multiply
BD*5.5 = 4.3*5.3
BD*5.5 = 22.79
Divide both sides by 5.5
BD = 22.79/5.5
BD = 4.1 (to 1 decimal place)