Answer:
Radius = 7
Explanation:
Since BA is tangent to circle O, it creates a 90° angle with the radius
Therefore, you can use Pythagorean theorem to solve this problem
a² + b² = c²
Let's say a is the radius
b is 5
c is 8.6
a² + 5² = 8.6²
a² + 25 = 73.96
Subtract 25 from both sides
a² = 48.96
Root both sides
a ≈ 6.997142274