Answer:
..let x be the side of the square garden, (x+1) the side of the equilateral triangle garden
square garden perimeter = x*4 = 4x
equilateral triangle garden perimeter = 3(x+1)= 3x+3
the 2 gardens have the same perimeter
4x=3x+3
we solve the equation to find the value of x
4x=3x+3
4x-3x=3
x=3
square garden side: 3m
garden side equilateral triangle: 3+1=4m