A candy manufacture puts 240 pieces

72 cm²

Step-by-step explanation:

The diagonal of the square divides the square into 2 right triangles.

let the legs of the triangle be x , then using Pythagoras' identity.

The square on the hypotenuse is equal to the sum of the squares on the other 2 sides.

The hypotenuse of the triangle is the diagonal, thus

x² + x² = 12²

2x² = 144 ( divide both sides by 2 )

x² = 72 ( take the square root of both sides )

x =

The area of the square = x² = ( )² = 72 cm²