Answer:
[tex]\huge\boxed{x=28\ ft}[/tex]
Step-by-step explanation:
If two rectangles are similar, then corresponding sides are in proportion.
Therefore we have the equation:
[tex]\dfrac{x}{42}=\dfrac{36}{54}[/tex]
cross multiply
[tex]54x=(42)(36)\\\\54x=1512[/tex]
divide both sides by 54
[tex]\dfrac{54x}{54}=\dfrac{15212}{54}\\\\x=28[/tex]
