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

Diameter $= 10$ units
One end point is at $\left(- 3 , - 4\right)$ at the 3rd Quadrant, therefore , the other end is located at $\left(3 , 4\right)$ at the 1st Quadrant. Both points are $5$ units away from the Origin $\left(0 , 0\right)$.