80cm = 1 rectangle length + 1 rectangle breadth

But notice that 4 rectangle breadths = 1 rectangle length

So 80cm = 4 rectangle breadths + 1 rectane breadth
= 5 rectangle breadths

1 rectangle breadth = 80cm ÷ 5 = 16cm

So 1 length of rectangle = 16cm x 4 = 64cm

Length of carpet (not rectangle, don't mix up the two)

= Length of 2 rectangles + breadth of 4 rectangles

= 2 x 64cm + 4 x 16cm
= 128cm + 64cm
= 192cm

Perimeter of carpet

= 2 lengths of carpet + 2 breadths of carpet

= 2 x 192cm + 2 x 80cm

= 384cm + 160cm

= 544cm

Cloe, you have forgotten to add the last part to your 6 units. That last part is actually adding up to 1 rectangle length

So final answer should be 480cm + 64cm = 544cm

Thank you :)