Question

A circle has the equation x2 + (y−7)2 = 121. What is the length of the diameter of the circle?

Answer 1

22

Explanation:

The standard form for an equation of a circle is
`(x-h)^2+(y-k)^2=r^2`, where h is the x coordinate of the center of the circle, k is the y coordinate, and r is the radius of the circle. Therefore, the radius of this circle squared is 121, meaning that the radius of the circle is 11. Since the diameter of a circle is twice the radius, the radius of this circle is 22. Hope this helps!