## izziewoods 2 years ago If a radius bisects a chord, then the lengths of the parts of the radius on either side of the chord are equal. A. Given B. Unfounded C. Definition of supplementary angles D. Definition of a bisector E. Definition of radius I don't get this at all... can anybody explain this to me really easily?

1. ganeshie8

the question talks about radius and chords. so lets begin wid drawing a circle, its radius and some chord

2. izziewoods

ok!

3. izziewoods

oh do you want me to draw it?

4. ganeshie8

yes if u can it wud be good :)

5. izziewoods

|dw:1355040041898:dw|

6. izziewoods

so line segment CD is the chord and the radius is line segment AB

7. izziewoods

am I right so far?

8. izziewoods

what should I do next?

9. mathstudent55

Didn't we just do this?

10. izziewoods

@mathstudent55 yes but I am not sure with my answer. you said that just because a chord is perpendicular to a radius, it does not necessarily bisect the radius right?

11. mathstudent55

right

12. izziewoods

so this question is asking about the length of the radius? like I'm not understanding the question well

13. mathstudent55

You knew from before that if a chord is perpendicular to a radius, the radius bisects the chord. Here they're asking you the other way around. If a chord is perpendicular to a radius, does the chord bisect the radius?

14. mathstudent55

|dw:1355040622608:dw|

15. izziewoods

oh then the answer is no

16. mathstudent55

Look at the three chords, one you drew and two I added. Let's say the radius is perpendicular to all 3 chords. Then you know the radius bisects all three chords. Now look at the chords. Only one chord can possibly be a bisector of the radius, but certainly not all three. In reality, there is an infinite number of chords that are perpendicular to that radius, and only one bisects the radius. So to conclude that with any chord that is perpendicular to a radius, that chord bisects the radius it's unfounded.

17. izziewoods

ohhhhh ok I think I get it!! ohohoh omg I get it!!! yeah!!!only one chord bisects the radius!!

18. mathstudent55

Right, but the radius bisects every chord that it is perpendicular to.

19. izziewoods

yes yes!!! thank you thank you thank you!!! I totally get it now!! you explained it to me really easily!!

20. mathstudent55

ok, great, you're welcome