Answer:
[tex]\mathrm{48 \:feet}[/tex]
Step-by-step explanation:
Use the Pythagorean theorem.
[tex]a^2+b^2=c^2[/tex]
[tex]20^2+b^2=52^2[/tex]
[tex]20^2+b^2-20^2=52^2-20^2[/tex]
[tex]b^2=2304[/tex]
[tex]b=\sqrt{2304}=48[/tex]
