Answer:
[tex]L=3h[/tex]
Step-by-step explanation:
Let height of a banner be [tex]h[/tex], then we know that this is [tex]\frac{1}{3}[/tex] of the length [tex]L[/tex] of the banner; so we have
[tex]h=\frac{1}{3} L[/tex] .
Now we can rearrange this equation to solve for the length of the banner given it's height:
[tex]L=3h[/tex]
So there we have it!
If the banner is 5 ft tall, then it's length will be:
[tex]L=3*5=15ft[/tex]