Question

If there are $15$ points on a circle, how many triangles can be formed?

• A. $455$
• B. $459$
• C. $490$
• D. $465$

Answer 1

The correct option is A $455$

There are $15$ points on a circle

We need three points to form a triangle

Therefore numbber of triangles ${=}^{15}{C}_3$

$=\frac{15\times 14\times 13}{1\times 2\times 3}=455$

Hence the number of triangles formed is $455$