Compare the area of a square and the area of a rectangle if you know that one side of the rectangle is √10

Compare the area of a square and the area of a rectangle if you know that one side of the rectangle is √10 cm longer and the other is √10 cm shorter than the side of the square.

We define that the side of the square is a cm, then we get that the sides of the rectangle:
(a + √10) cm – length;
(a – √10) cm – width.
Find the areas of a square and a rectangle:
S square = a² (cm²);
S straight = (a + √10) * (a – √10) = a² – 10 (cm²).
a²> a² – 10.
Answer: the area of the square is 10 cm² larger than the area of the rectangle.