Let x be the width so that 2x-4 is the length, both in cm.

The perimeter of a rectangle is given by: P=2l+2w

where l is the length and w is the width.

Given a perimeter of 40 cm, we can write: 40=2(2x-4)+2(x)

Solve for x. Divide both sides by 2: 20=(2x-4)+

20=3x-4

24=3x

8=x

So, the dimensions of the rectangle are: length: 2x-4=2(8)-4=12cm

width: x=8 cm

The perimeter of a rectangle is given by: P=2l+2w

where l is the length and w is the width.

Given a perimeter of 40 cm, we can write: 40=2(2x-4)+2(x)

Solve for x. Divide both sides by 2: 20=(2x-4)+

20=3x-4

24=3x

8=x

So, the dimensions of the rectangle are: length: 2x-4=2(8)-4=12cm

width: x=8 cm