Answer: ~ 5.45 m
Step-by-step explanation: The pole would create an altitude for the triangle, and the wire attached from the ground to the pole would be create a hypotenuse of 12m. Since the wire makes a 63 degree angle with the ground, we can use a trig ratio to find the base. The base of the triangle would be the distance from the wire in the ground to the pole itself. Using cosine, (adjacent to 63 degrees over 12m) you can find the measure of the base.
cos (63 deg.) = x / 12
12 • cos (63 deg.) = x
5.44788599687 = x.
Hope this helps! (Added pic for clarity!)