Given, Perimeter = 72 m 

Let the breadth of the rectangle be x meters, 

Then the length of the rectangle is 2x meter. 

We know that the perimeter of a rectangle = 2(l + b) 

∴ According to the question: $2(2\mathrm{x}+\mathrm{x})=72$ 

=> 4x + 2x = 72

=> 6x = 72

=> x = 12

Hence, the required length of the rectangle = 2 x 12 = 24 m and  

The breadth of the rectangle =12 m.