Answer: Â 120 ft
Step-by-step explanation:
The Ellipse equation is: Â [tex]\dfrac{(x-h)^2}{a^2}-\dfrac{(y-k)^2}{b^2}=1[/tex] Â Â Â where
- (h, k) is the center
- "a" is the horizontal radius
- "b" is the vertical radius
- c is the distance from the center to the foci: |a² - b²| = c²
Given: horizontal diameter = 122  →  horizontal radius = 61 = a
     vertical diameter = 22  →  vertical radius = 11 = b
Foci (c):  61² - 11² = c²
      3721 - 121 = c²
         3600 = c²
          ±60 = c
Let (h, k) = (0, 0)
Then the foci are located at -60 and +60.
The distance between them is 60 + 60 = 120