Answer:
3
Step-by-step explanation:
The lights and pole form a right triangle. The question gives the hypotenuse as 5 and one side length as 4.
Use the Pythagorean theorem: [tex]a^2+b^2=c^2[/tex].
Plug in what you are given: [tex]4^2+b^2=5^2[/tex]
[tex]16+b^2=25[/tex]
[tex]b^2=9[/tex]
b = 3
Or you could recognize that it was a pythagorean triple: 3, 4, 5
