Answer:54 cm
Step-by-step explanation:
Given
Rods are joined to form a square
Perimeter of square is [tex]72\ cm[/tex]
Suppose a is the length of each rod so
Perimeter is [tex]4 a[/tex]
[tex]\therefore 4a=72[/tex]
[tex]\Rightarrow a=\frac{72}{4}[/tex]
[tex]\Rightarrow a=18\ cm[/tex]
Now if rods are joined to form a square then
Perimeter is the sum of sides
Perimeter of (equilateral)triangle[tex]=3a[/tex]
[tex]\Rightarrow =3\times 18[/tex]
[tex]\Rightarrow =54\ cm[/tex]