For the square to fit inside the circle without touching it, the diagonal of the square needs to be less than the diameter of the circle.
Using the Pythagorean theorem we can calculate the diagonal of the square:
X = SQRT(5^2 + 5^2)
X = SQRT(25 + 25)
X = SQRT(50)
X = 7.07
The diagonal of the square is 7.07 cm, which is less than the diameter of the circle, 9cm, so it will fit .
If you put 0 in the place of x or y, which every one you choose, it will cancel it or and you can just divide the number next to it by the answer (-20, 20). Take it one step at a time, don't try to do both at the same time.
