Answer:
Step-by-step explanation:
AB is a tangent to circle o
ABO is a right-angled
AO²=AB²+BO²
[tex]BO=\sqrt{AO^{2}-(AB)^{2})\\}\\\\\sqrt{(8.6)^{2}-(5)^{2} } \\\\=\sqrt{73.96-25} \\\\=\sqrt{48.9} \\\\=6.99\\\\Answer=7[/tex]
hope it helps....
have a great day :)
