You can put this solution on YOUR website! The other tutor assumed a square not just a rectangle.
There is not enough info to find the sides of a rectangle.
2*(W+L)=380
W+L=190
any combo of sides that add up to 190 could be the sides of the rectangle.
1 and 189
2 and 188
etc
and the sides don't have to be whole numbers.
.5 and 189.5