Final answer:
The length of the diagonal of the square is 5.
Step-by-step explanation:
To find the length of the diagonal of a square, we can use the Pythagorean theorem. The Pythagorean theorem states that in a right triangle, the square of the length of the hypotenuse (the longest side) is equal to the sum of the squares of the lengths of the other two sides. In this case, the legs of the square are 4 and 3. Let's use the equation a^2 + b^2 = c^2 to find the length of the diagonal:
4^2 + 3^2 = c^2
16 + 9 = c^2
25 = c^2
c = √25
c = 5
Therefore, the length of the diagonal of the square is 5.