# Thread: What is the length of the radius of the circle? Can anyone please explain this?

1. ## What is the length of the radius of the circle? Can anyone please explain this?

Hey, can anyone lend me a hand here? All I need is an explination as to how to do these.Or send me a website that can explain it. I can't figure it out. Thanks! :0D

5. If the diameter of the circle has endpoints at (-2, 4) and (3, 8), what is the length of the radius of the circle?

6. If the endpoints of the diameter of a circle are (-10, 12) and (12, 18), what are the coordinates of the center of the circle?

2. Originally Posted by amandaggogo
Hey, can anyone lend me a hand here? All I need is an explination as to how to do these.Or send me a website that can explain it. I can't figure it out. Thanks! :0D

5. If the diameter of the circle has endpoints at (-2, 4) and (3, 8), what is the length of the radius of the circle?

6. If the endpoints of the diameter of a circle are (-10, 12) and (12, 18), what are the coordinates of the center of the circle?

5. The radius of the circle is half the length of the diameter. Do you know a formula for the length of a line segment? If so, plug in the two endpoints, find the length of the diameter and divide by 2.

6. The coordinates of the center of the circle are those of the point at the midpoint of the line segment joining your two points. Do you have a formula for the midpoint of two points? If so, plug those two points in and you will get the midpoint of your circle.

3. Originally Posted by amandaggogo
5. If the diameter of the circle has endpoints at (-2, 4) and (3, 8), what is the length of the radius of the circle?
Plug the endpoints into the Distance Formula to find the length of the diameter. Then divide by "2" to find the length of the radius.

Originally Posted by amandaggogo
6. If the endpoints of the diameter of a circle are (-10, 12) and (12, 18), what are the coordinates of the center of the circle?
Plug the endpoints into the Midpoint Formula to find the coordinates of the diameter's midpoint, which is of course also the center.

4. Thanks for the help yall! :0)