The circumference measurements form an arithmetic progression with the first term \(a = 5.00\) m and the second term \(a + d = 5.02\) m, where \(d\) is the common difference.

Thus, \(d = 5.02 - 5.00 = 0.02\) m.

The formula for the \(n\)-th term of an arithmetic progression is \(a_n = a + (n-1) imes d\).

We need to find the circumference 20 years after the first measurement, which is the 21st term (since the first measurement is at year 0).

\(a_{21} = 5.00 + (21-1) imes 0.02\)

\(a_{21} = 5.00 + 20 imes 0.02\)

\(a_{21} = 5.00 + 0.40\)

\(a_{21} = 5.40\) m