Question 750076
Pythagoras.

The pole and the shadow are two sides of 
a right angled triangle. The rope makes 
the hypotenuse.
Therefore:
(Length of pole)^2 + (length of shadow)^2 
= (Length of rope )^2
(10)^2 + (8)^2 = (Length of rope)^2
(Length of rope)^2 = 164
Length of rope = square root of 164
Length of rope = 12.8feet
:-)