# Math

posted by .

How many chords are determined by seven points on a circle?

How do you do it, not answer.

• URGENT! MATH! HELP! -

How many chords are determined by seven points on a circle?

How do you do it, not answer.

• Math -

each point of the 7 is connected to 6 others.

So, going through all 7 points, you have 7*6 = 42 connections.

But, having gone all the way around, you have drawn each chord twice, once from each end. So, divide the total by 2 to get

7*6/2 = 21 chords

## Similar Questions

1. ### math

the number of noncollinear points needed to determine a circle Two. The location of the center, and one point on the circle (ie, the length of radius), you have determined the circle. However, the circle thus determined can be an an …
2. ### maths

eight points lie on the circumference of a circle. one of them is labelled P. chords join some or all of the pairs of these points so that the seven points other than P lie on different numbers of chords. what is the minimum number …
3. ### math

n points are arranged on a cirlce and all the chords drawn. Let I(n) be the number of intersection points inside the circle if no 3 chords are concurrent. Find a formula for I(n).
4. ### math

n points are arranged on a cirlce and all the chords drawn. Let I(n) be the number of intersection points inside the circle if no 3 chords are concurrent. Find a formula for I(n).
5. ### Circle Geometry - chords in a circle

Let PQ, RS , and TU be parallel chords of a circle. The distance between chords PQ and RS is 4, and the distance between chords RS and TU is also 4. If PQ = 78 TU=50 , then find RS. how to do this?
6. ### Geometry

Two points are chosen uniformly at random on the unit circle and joined to make a chord C1. This process is repeated 17 more times to get chords C2,C3,…,C18. What is the expected number of pairs of chords that intersect?
7. ### Math

Two points are chosen uniformly at random on the unit circle and joined to make a chord C1. This process is repeated 17 more times to get chords C2,C3,…,C18. What is the expected number of pairs of chords that intersect?
8. ### Math Help

Two points are chosen uniformly at random on the unit circle and joined to make a chord C1. This process is repeated 17 more times to get chords C2,C3,…,C18. What is the expected number of pairs of chords that intersect?
9. ### math

PQ and RS are 2 parallel chords of a circle such that PQ = 8 cm & RS = 6 cm. If the chords are on the opposite sides of the centre and distance between them is 4 cm. find the radius of the circle
10. ### Maths

Around a circle i place 64 equally spaced points, so that there are 64x63 divided by2=2016 possible chords between these points. I draw some of these chords, but each chord cannot cut across more than one other chord. What is the maximum …

More Similar Questions