Answer:
52 units
Explanation:
We know that,
A perpendicular bisector cuts a line segment into two equal parts at 90°.
As, CB is a perpendicular bisector of AD. So, it cuts AD into 2 equal parts.
We have,
AB = DB
i.e. 7x + 10 = 9x - 2
i.e. 7x - 9x = -2 - 10
i.e. -2x = -12
i.e. x = 6.
Thus, AB = 7x + 10 = 7×6 + 10 = 42 + 10 = 52.
Hence, the length of AB is 52 units.