To find similarity ratio a:b
We take the sides and make a proportion
[tex]\frac{height \ of \ smaller \ cone}{height \ of \ larger \ cone} = \frac{radius \ of \ smaller \ cone}{radius \ of \ larger \ cone}[/tex]
[tex]\frac{9}{15} = \frac{6}{10}[/tex]
[tex]\frac{3}{5} = \frac{3}{5}[/tex]
So the ratio a:b is 3:5
