* A is one leg (750mm)

* B is the other leg (1000mm)

* The diagonal is the hypotenuse.

To find the length of the diagonal (hypotenuse), you can use the Pythagorean theorem:

a² + b² = c²

Where:

* a = length of one leg

* b = length of the other leg

* c = length of the hypotenuse (the diagonal)

1. Substitute the values:

750² + 1000² = c²

2. Calculate:

562,500 + 1,000,000 = c²

1,562,500 = c²

3. Find the square root:

c = √1,562,500

c ≈ 1250 mm

Therefore, the length of the diagonal is approximately 1250 mm.