#### Answer

The height of the cable must be 76 meters.

#### Work Step by Step

As per the given statement , we have vertical height of the tower: $y=160$
and Diameter = 1280 meter. This implies that Radius: $2x=1280 \implies x=640$
Now, consider $x^2=4py$
This implies that $(640)^2=(4p)(160) \implies p=640$
As the cable 200 meters from a tower.
This means that $x=640-200=440$
and $(440)^2=(4)(640)y \implies y=75.625 \approx 76$
Hence, the height of the cable must be 76 meters.