Answer:
x = 3
Step-by-step explanation:
Side lenght of square = (x + 3)
Side length of equilateral triangle = (3x - 1)
It is Given that:
Perimeter of square = Perimeter of equilateral triangle
4 times side length of square = 3 times side length of equilateral triangle.
[tex] \therefore \: 4(x + 3) = 3(3x - 1) \\ \\ \therefore \: 4x + 12 = 9x - 3 \\ \\ \therefore \:12 + 3 = 9x - 4x \\ \\ \therefore \:15 = 5x \\ \\ \therefore \:x = \frac{15}{5} \\ \\ \huge \red{ \boxed{\therefore \:x = 3}}[/tex]
