Final answer:
The question is a geometric problem involving calculating the length of a chord given the radius of a circle and the middle ordinate. Use the Pythagorean theorem to find the chord length and round to the nearest tenth.
Step-by-step explanation:
The question deals with a geometry problem, specifically relating to circles and chords.
Steps to Solve the Problem:
1. The middle ordinate is the perpendicular line from the midpoint of the chord to the circumference of the circle (or arc).
2. Knowing the middle ordinate (6ft) and the radius (70ft), we can visualize a right triangle formed by the middle ordinate, half of the chord length, and the radius.
3. According to the Pythagorean theorem, the square of the radius (r) is equal to the square of half of the chord length (c/2) plus the square of the middle ordinate (m).
4. This gives us the equation r^2 = (c/2)^2 + m^2.
5. Plugging the given measurements into the equation, we get 70^2 = (c/2)^2 + 6^2.
6. After solving for c/2, calculate the full chord length by multiplying the result by 2. Round off to the nearest tenth of a foot.