What decimal precision should be given for the diagonal so that length can be calculated properly for a rectangle
    The diagonal of a rectangle is 15.62 inches and the width is 10 inches. What is the length? _____ inches

The answer is length = 12 inches. 

If you have a precision of 2 decimal places in the diagonal, it doesn't result in an exact value for the length.

Is this question appropriate for school children or should I give a precision of 3 decimal places so that length can be calculated properly?
What decimal precision should be given for the diagonal so that length can be calculated properly for a rectangle
===

    The diagonal of a rectangle is 15.62 inches and the width is 10 inches. What is the length? _____ inches

The answer is length = 12 inches. 

If you have a precision of 2 decimal places in the diagonal, it doesn't result in an exact value for the length.

Is this question appropriate for school children or should I give a precision of 3 decimal places so that length can be calculated properly?