Answer:
30 meters
Step-by-step explanation:
Let the side length of the square plot is x meters.
So, the length of the rectangular building is [tex]\frac{x}{3}[/tex] meters and the width of the building is [tex]\frac{x}{4}[/tex] meters.
So, area of the the building rectangle is [tex]\frac{x}{3} \times\frac{x}{4} =\frac{x^{2} }{12}= 75[/tex] {Given}
⇒ [tex]x^{2} = 75 \times 12 = 900[/tex]
⇒ x = 30 meters (Answer)