Math
posted by dddd47906 .
How many chords are determined by seven points on a circle?
How do you do it, not answer.

How many chords are determined by seven points on a circle?
How do you do it, not answer. 
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