There are 10 points on a circle. By joining them how many chords can be drawn?

If 20 points are marked on a circle, how many chords can be drawn?

There are 10 non collinear points in a plane. By joining them how many triangles can be made?

How many chords we can draw a circle?

Seven points lie on a circle. How many chords can be drawn by joining these points.

Seven points lie on a circle. How many chords can be drawn by joining these points.

There are 21 points on circle . The number of chord by joining there points are ............. .

How many chords can be drawn through 21 points?

If A, B, C, D, E and F are 6 distinct points on the circumference of a circle, how many different chords can be drawn using any 2 of the 6 points ?