It is given that Emily is 12 feet away from light pole and distance between Emily to a point of tangency on the pole is 24 feet.
So the diagram is
Here x is the radius of the light pole.
Use the Pythagoras theorem , to find x.
[tex]24^2=12^2+x^2[/tex][tex]576=144+x^2[/tex][tex]x^2=576-144[/tex][tex]x=\sqrt[]{432}[/tex][tex]x=20.78[/tex]Hence the radius of light pole is 20.78 feet.