The area of the square A will be :

25

The correct answer is Option 2: 25

The given figure forms a right-angled triangle with sides 3 cm and 4 cm. The side of square A is the hypotenuse of this triangle.

Using Pythagoras theorem:
3² + 4² = 9 + 16 = 25
⇒ hypotenuse = √25 = 5 cm

Now, area of square = side²
= 5² = 25 cm²

Therefore, the area of square A is 25 cm².