A rectangular swimming pool is 21 meters wide and 50 meters long. Calculate the length of the diagonal to 1 decimal place.

1. Use the Pythagorean theorem to find the diagonal of the pool:

c = \sqrt{a^2 + b^2}

2. Substitute the given values \(a = 21\) and \(b = 50\):

c = \sqrt{21^2 + 50^2}

3. Calculate \( 21^2 \) and \( 50^2 \):

21^2 = 441

50^2 = 2500

4. Add these values:

441 + 2500 = 2941

5. Take the square root of 2941:

\sqrt{2941} \approx 54.2

Therefore, the length of the diagonal is 54.2 .