A hall 130 feet in length was designed as a whispering gallery. If the ceiling is 25 feet high at the center, how far from the center are the foci located?

60 feet from the center.

Step-by-step explanation:

As this it was designed as whispering gallery, and we know the whole length of the hall, and the highness of the ceiling we can use the following expression:

c² = a² - b²   (1)

Where:

c: Length from center to foci.

a: length of half the hall.

b: length of the ceiling.

Replacing the given data into (1) we have:

c² = (130/2)² - (25)²

c = √65² - 500

c = √3600

Hope this helps

phosphate, calcium ion, chloride ion, neon atom

step-by-step explanation:

i can't see the picture : /