# Find the type of triangle from the given sides

Given three integers A, B, and C which denotes the sides of a triangle, the task is to check that the triangle is a right-angled, acute-angled or obtuse-angled triangle.

Examples:

Input: A = 1, B = 4, C = 3
Output: Obtuse-angled Triangle
Explanation:
Triangle with the sides 1, 2 and 3 is an obtuse-angled triangle

Input: A = 2, B = 2, C = 2
Output: Acute-angled Triangle
Explanation:
Triangle with the sides 2, 2, and 2 is an acute-angled triangle

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: The idea is to use the facts from the cosine law to check the type of triangle using this formulae – It generalizes the Pythagorean Theorum, which states that for a right-angled triangle square of the hypotenuse is equal to the sum of squares of the base and height of the triangle, which is Similarly, It can be observed that
For acute-angled triangle For Obtuse-angled triangle Below is the implementation of the above approach:

## C++

 // C++ implementation to find  // the type of triangle with  // the help of the sides     #include  using namespace std;     // Function to find the type of  // triangle with the help of sides  void checkTypeOfTriangle(int a,                   int b, int c){      int sqa = pow(a, 2);      int sqb = pow(b, 2);      int sqc = pow(c, 2);             if (sqa == sqa + sqb ||           sqb == sqa + sqc ||           sqc == sqa + sqb){          cout << "Right-angled Triangle";      }      else if(sqa > sqc + sqb ||              sqb > sqa + sqc ||              sqc > sqa + sqb){          cout << "Obtuse-angled Triangle";      }      else{          cout << "Acute-angled Triangle";      }  }     // Driver Code  int main()  {      int a, b, c;      a = 2;      b = 2;       c = 2;             // Function Call      checkTypeOfTriangle(a, b, c);      return 0;  }

## Java

 // Java implementation to find  // the type of triangle with  // the help of the sides  import java.util.*;     class GFG  {     // Function to find the type of  // triangle with the help of sides  static void checkTypeOfTriangle(int a,                   int b, int c){      int sqa = (int)Math.pow(a, 2);      int sqb = (int)Math.pow(b, 2);      int sqc = (int)Math.pow(c, 2);             if (sqa == sqa + sqb ||           sqb == sqa + sqc ||           sqc == sqa + sqb){          System.out.print("Right-angled Triangle");      }      else if(sqa > sqc + sqb ||              sqb > sqa + sqc ||              sqc > sqa + sqb){          System.out.print("Obtuse-angled Triangle");      }      else{          System.out.print( "Acute-angled Triangle");      }  }     // Driver Code   public static void main (String []args)  {      int a, b, c;      a = 2;      b = 2;       c = 2;             // Function Call      checkTypeOfTriangle(a, b, c);  }  }     // This code is contribute by chitranayal

## Python3

 # Python3 implementation to find  # the type of triangle with  # the help of the sides     # Function to find the type of  # triangle with the help of sides  def checkTypeOfTriangle(a,b,c):      sqa = pow(a, 2)      sqb = pow(b, 2)      sqc = pow(c, 2)         if (sqa == sqa + sqb or         sqb == sqa + sqc or         sqc == sqa + sqb):          print("Right-angled Triangle")         elif(sqa > sqc + sqb or             sqb > sqa + sqc or             sqc > sqa + sqb):          print("Obtuse-angled Triangle")         else:          print("Acute-angled Triangle")     # Driver Code  if __name__ == '__main__':      a = 2     b = 2     c = 2        # Function Call      checkTypeOfTriangle(a, b, c)     # This code is contributed by mohit kumar 29

## C#

 // C# implementation to find  // the type of triangle with  // the help of the sides  using System;     class GFG  {      // Function to find the type of  // triangle with the help of sides  static void checkTypeOfTriangle(int a,                   int b, int c){      int sqa = (int)Math.Pow(a, 2);      int sqb = (int)Math.Pow(b, 2);      int sqc = (int)Math.Pow(c, 2);              if (sqa == sqa + sqb ||           sqb == sqa + sqc ||           sqc == sqa + sqb){          Console.Write("Right-angled Triangle");      }      else if(sqa > sqc + sqb ||              sqb > sqa + sqc ||              sqc > sqa + sqb){          Console.Write("Obtuse-angled Triangle");      }      else{          Console.Write( "Acute-angled Triangle");      }  }      // Driver Code   public static void Main(String []args)  {      int a, b, c;      a = 2;      b = 2;       c = 2;              // Function Call      checkTypeOfTriangle(a, b, c);  }  }     // This code is contributed by 29AjayKumar

Output:

Acute-angled Triangle


Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.

My Personal Notes arrow_drop_up Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.