Answer:
20.4
Step-by-step explanation:
The rule for secants is pretty simple. The product of the distance to one intersection with the circle and the distance to the other intersection with the circle is a constant. (This same rule applies when the secants intersect outside the circle.)
Here, that means ...
8 × 23 = 9 × x
x = 8·23/9 ≈ 20.4 . . . . . divide by 9
