So basically what you want to do is square root this, since to find the area of a square from the side length, you square it, (x * x, because the area for a quadrilateral is base * height, and a square has the same length of sides).
So there is no way to properly square root a number unless you memorize it. However, what you can do, is look at the last digit and make an approximation, at which two numbers multiply together to have a last digit of 6.
So, 4 * 4 and 6 * 6 are the two that square to have a last digit of 6.
(1: 1, 2: 4, 3: 9, 4: 6, 5: 5, 6: 6, 7: 9, 8: 4, 9: 1, 0: 0) If that makes any sense.
So basically the square root has to end with 4 or 6.
Now, you can just approximate. It would be over 20, because 20 squared (20 * 20) is equal to 400. But it would be under 30, because 30 squared is 900.
So the two possible numbers are 24 and 26.
If you square both of them, you find that:
24 squared = 576
26 squared = 676
So therefore 26 is the square root of 676, so therefore one side is 26 yards.
