CAT 1993 — QA Question 34
Basics of QuadrilateralsEasy
Consider the five points comprising of the vertices of a square and the intersection point of its diagonals. How many triangles can be formed using these points?
Answer & solution
Correct answer: 8
- A
4
- B
6
8
- D
10
Solution
We can form a triangle with any 3 points which are not collinear.
3 points out of 5 can be chosen in 5C3 = 10 ways.
But of these, the three points lying on the two diagonals will be collinear.
So 10 – 2 = 8 triangles can be formed.
Hence, option (c).