How many chords can be drawn through 21 points on a circle?

Asked by Pragya Singh | 1 year ago |  66

##### Solution :-

Given 21 points on a circle

We know that we require two points on the circle to draw a chord

Number of chords is are

21C2=

$$\dfrac{21!}{2!(21-2)!}=\dfrac{21\times 20\times 19!}{2!\times 19!}$$

$$\dfrac{21\times 20}{2\times 1}$$

$$\dfrac{420}{2}=210$$

Total number of chords can be drawn are 210

Answered by Abhisek | 1 year ago

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