I'm assuming you're looking for the dimensions of the plot. I'm going with that. ;) If the length of the plot is 5 meters longer than the width, then L = w + 5. The area for a rectangle is L*w, and we have an area value of 20,000 so our formula is 20000=(w+5)(w) and 
. We will bring the 20,000 over by subtraction and set the polynomial equal to 0 to factor and solve for w. 
Solving for w we get values of w=138.9 and -143.9. Of course the 2 things in math that will never EVER be negative are time and distance/length, so -143.9 is out. Our width is 138.9 and the length is 138.9 + 5 so the length is 143.9. And there you go! Hope that's what you needed!