# Number of triangles in a plane if no more than two points are collinear

Given n points in a plane and no more than two points are collinear, the task is to count the number of triangles in a given plane.

Examples:

```Input :  n = 3
Output : 1

Input :  n = 4
Output : 4
```

Let there are n points in a plane and no three or more points are collinear then number of triangles in the given plane is given by

## C++

 `// C++ program to find the number of ` `// triangles in a plane if no more ` `// then two points are collinear. ` `#include ` `using` `namespace` `std; ` ` `  `// Function to find number of triangles ` `// in a plane. ` `int` `countNumberOfTriangles(``int` `n) ` `{ ` ` `  `    ``// Formula to find number of triangles ` `    ``// nC3 = n * (n - 1) * (n - 2) / 6 ` `    ``return` `n * (n - 1) * (n - 2) / 6; ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``int` `n = 4; ` `    ``cout << countNumberOfTriangles(n); ` `    ``return` `0; ` `} `

## Java

 `// Java program to find the number of ` `// triangles in a plane if no more ` `// then two points are collinear. ` `import` `java.io.*; ` ` `  `class` `GFG { ` ` `  `    ``// Function to find number of triangles ` `    ``// in a plane. ` `    ``static` `int` `countNumberOfTriangles(``int` `n) ` `    ``{ ` ` `  `        ``// Formula to find number of triangle ` `        ``// nC3 = n * (n - 1) * (n - 2) / 6 ` `        ``return` `n * (n - ``1``) * (n - ``2``) / ``6``; ` `    ``} ` ` `  `    ``// Driver code ` `    ``public` `static` `void` `main(String[] args) ` `    ``{ ` `        ``int` `n = ``4``; ` ` `  `        ``System.out.println( ` `            ``countNumberOfTriangles(n)); ` `    ``} ` `} `

## Python3

 `# Python3 program to find  ` `# the number of triangles  ` `# in a plane if no more ` `# then two points are collinear. ` ` `  `# Function to find number ` `# of triangles in a plane. ` `def` `countNumberOfTriangles(n) : ` `     `  `    ``# Formula to find  ` `    ``# number of triangles ` `    ``# nC3 = n * (n - 1) * ` `    ``# (n - 2) / 6 ` `    ``return` `(n ``*` `(n ``-` `1``) ``*`  `                ``(n ``-` `2``) ``/``/` `6``) ` ` `  `# Driver Code ` `if` `__name__ ``=``=` `'__main__'` `: ` `     `  `    ``n ``=` `4` `    ``print``(countNumberOfTriangles(n)) ` ` `  `                 `  `# This code is contributed ` `# by ajit `

## C#

 `// C# program to find the  ` `// number of triangles in  ` `// a plane if no more then  ` `// two points are collinear. ` `using` `System; ` ` `  `class` `GFG  ` `{ ` ` `  `    ``// Function to find number ` `    ``// of triangles in a plane. ` `    ``static` `int` `countNumberOfTriangles(``int` `n) ` `    ``{ ` ` `  `        ``// Formula to find number  ` `        ``// of triangle  ` `        ``// nC3 = n * (n - 1) * ` `        ``//           (n - 2) / 6 ` `        ``return` `n * (n - 1) *  ` `                   ``(n - 2) / 6; ` `    ``} ` ` `  `    ``// Driver code ` `    ``public` `static` `void` `Main() ` `    ``{ ` `        ``int` `n = 4; ` ` `  `        ``Console.WriteLine( ` `            ``countNumberOfTriangles(n)); ` `    ``} ` `} ` ` `  `// This code is contributed by anuj_67. `

## PHP

 ` `

Output:

```4
```