Answer
14.4 ft~
Step-by-step explanation
A kite is flying 12 feet off the ground, therefore the height is 12 (assuming the line is tied to the ground if a person is holding the line then the height would be less)
Assuming the sun is positioned in such a way that the shadow represents a horizontal distance. Horizontal distance of shadow = 8
Use Pythagoras Theorem
Where a^2 + b^2 = c^2
8^2 + 12^2 = 208
Square root 208 = 14.4~
~ Hoodini, here to help :)