Question 134838
I think you meant to say 1 meter of cable is to be used for tying.  At least I hope so, because I don't know how long 1, is.


1 meter down from the top of the pole makes one side of the triangle 5 meters.  Using 1 meter of the 6.5 meter cable for tying leaves 5.5 meters for the hypotenuse of the triangle.


Pythagoras says:  {{{a=sqrt(c^2-b^2)}}} where {{{b=5}}} and {{{c=5.5=11/2}}}


{{{a=sqrt((11/2)^2-5^2)}}}


{{{a=sqrt(121/4-25)}}}


{{{a=sqrt(121/4-100/4)=sqrt(21/4)=sqrt(21)/2}}} meters