The perimeter of a rectangle is twice the sum of its length and its width. the perimete is 28 meters and its length is 2 meters more than twice its width. what is its length?

Let l be length and w be width.
So the problem already gave you what a perimeter is, which is 2l + 2w.
Now it says perimeter is 28, so 2l + 2w = 28.
Then it says length is 2 more than twice its width, so l = 2w + 2.
Now substitute.
2(2w + 2) + 2w = 28
4w + 4 + 2w = 28
6w = 24
w = 4

Now substitute w back in l = 2w + 2
l = 2(4) + 2
l = 10