In the figure below, the sum of the side lengths of a and B squares is 20 cm. The area of a square is 40 cm larger than that of b square █□ ╰—╯ twenty Black a, white B! Have a formula for numbers! What does "^" stand for?

In the figure below, the sum of the side lengths of a and B squares is 20 cm. The area of a square is 40 cm larger than that of b square █□ ╰—╯ twenty Black a, white B! Have a formula for numbers! What does "^" stand for?

Let the side length of square B be x, then the side length of square a is 20-x
(20-x)^2-x^2=40
400-40x+x^2=40
360=40x
x=9
x^2=81
The area of square B is 81 square centimeters