Answer:
69
Step-by-step explanation:
[tex]x=13.7[/tex]
[tex]x=\sqrt{h^2-a^2}[/tex]
[tex]x=\sqrt{15^2-6^2}[/tex]
[tex]x=\sqrt{225-36}[/tex]
[tex]x=\sqrt{189}[/tex]
