Let A= original rectangle

B= new rectangle= original rectangle tripled

Remember that perimeter of a rectangle is

P= 2w + 2l

P= (2 * width) + (2 * length)

= 3( 2x + 2(x+3))= (6x+ 6x +18)

= 12x + 18= 66

Now solve for x.

12x+18= 66

12x= 48

x=4= original width

Original length: Plug in the original width (4) into l = w
+3

Original length = 7

The original perimeter:

Perimeter of A= 2(4) + 2(4 + 3)

Perimeter of A= 22

The original length of the original perimeter = 7