Question 6933
The formula you need to use is the following:

{{{ sqrt( (x[1]-x[2])^2 + (y[1]-y[2])^2)) }}}

Plugging in your given values this gives:

{{{ sqrt( (0-9)^2 + (8+6)^2)) }}}
{{{ sqrt( 81 + 196 ) }}}
{{{ sqrt( 277 ) }}} which is your answer.

Hope that helps.
Regards,
-Mike