The center of a circle is at the origin. An endpoint of a diameter of the circle is at (-3, -4). How long is the diameter of the circle?

Question

jhannybean · Answer

This is the same kind of question as your last one.

jhannybean · Answer

Equation of circle : $\large (x-h)^2 +(y-k)^2 =r^2 $

Center/(vertex) = $\large (h,k)= (0,0)$

plug it into formula $\large  {(x-0)^2 +(y-0)^2 = r^2 \ x^2 +y^2 =r^2}$

A diameter is made up of 2 radiuses. so we'd be solving for r^2. 

point given: $\large (-3,-4)$ 

$\large (-3)^2 +(-4)^2=r^2(\text{or} \ D)$

$\large D =?$

anonymous · Answer

10

anonymous · Answer

wait the answer is 5 right? because its 25 so the square root of that is 5

jhannybean · Answer

No, it would have been 25 because r^2 = D.