To find the length of the hypotenuse \(c\) using the Pythagorean theorem, we can use the formula:
\[
c = \sqrt{a^2 + b^2}
\]
where:
- \(a\) is one leg of the right triangle (the altitude in this case),
- \(b\) is the other leg (the base or adjacent side in this case),
- \(c\) is the hypotenuse.
Given:
- Altitude \(a = 6.6\) m,
- Base \(b = 4.1\) m.
Now we can plug in the values:
\[
c = \sqrt{(6.6)^2 + (4.1)^2}
\]
Calculating \(6.6^2\) and \(4.1^2\):
\[
6.6^2 = 43.56
\]
\[
4.1^2 = 16.81
\]
Now add those values together:
\[
c = \sqrt{43.56 + 16.81} = \sqrt{60.37}
\]
Now, calculating the square root:
\[
c \approx 7.77
\]
Rounding to the nearest tenth:
\[
c \approx 7.8 \text{ m}
\]
Thus, the length of the hypotenuse is approximately \( \boxed{7.8} \) m.