I found: length<span>=10cm</span> width<span>=7cm</span>
Explanation:
Call the length l, the width w and the perimeter P; you get:
<span>l=2w−4</span> <span>P=2l+2w</span>
Where <span>P=34cm</span>
so, substitute the first into the second for l:
<span>34=2<span>(<span>2w−4</span>)</span>+2w</span> <span>34=4w−8+2w</span> <span>6w=42</span> <span>w=<span>426</span>=7cm</span> use this into the irst equation: <span>l=2⋅7−4=14−4=10cm</span>
