Line segment AB is tangent to circle O at B. The diagram is not drawn to scale.

The figure is a circle O with a triangle A B O that has a vertex at the center and side A B tangent to the circle at point B. Side O B is labeled as length r.

IF AB = 9 and AO = 21.6, what is the length of the radius (r)? Round the answer to the nearest tenth.

(1 point)
Responses

15.3
15.3

21.2
21.2

19.6
19.6

12.6