A triangle can be broadly classified according to the length of its sides and the angle between the sides.
Based on the sides, there are three types of triangle
1. Equilateral Triangle
2. Isosceles Triangle
3. Scalene Triangle

Based on the angles, there are also 3 types:
1. Acute triangle
2. Right triangle
3. Obtuse triangle

In this article, we’ll be discussing triangles that are classified based on sides, and implementing the same in the program.

1. Equilateral Triangle: A triangle in which all sides are of the same length
2. Isosceles Triangle: A triangle in which exactly two sides are equal
3. Scalene Triangle: A triangle in which all sides are having different length

Approach to determine the type of a triangle

1. Read the length of a triangle for the user
2. If side1, side2 and side3 are equal to each other, then
   • print a message the triangle is an equilateral triangle
3.  If any two from side1, side2 or side3 are having the same length, then
   • print message the triangle is isosceles triangle
4.  If all three sides are different in length, then
   • print message the triangle is a scalene triangle

C Program To Check whether Triangle is Equilateral, Isosceles or Scalene

The program also implies Triangle Inequality Theorem to validate whether the given sides can be a triangle or not.

Program:

#include<conio.h>
#include<stdio.h>
#include<math.h>
void
main ()
{
  int a, b, c, flag = -1;
  printf (" Enter the values of a, b and c : = ");
  scanf ("%d %d %d", &a, &b, &c);
  if ((a >= 0 && a <= 10) && (b >= 0 && b <= 10) && (c >= 0 && c <= 10)){
 
 // Triangle Inequality Theorem : every side's length should be shorter than sum of other two side
      if (((a + b) > c) && ((b + c) > a) && ((c + a) > b)){
    flag = 1;
    if ((a == b) && (b == c))
      printf ("\n It is an Equilatral Triangle");
    else if ((a == b) || (b == c) || (c == a))
      printf ("\n It is an isosceles Triangle");
    else
      printf ("\n It is a Scalene Triangle");
      }
    }
    
  if (flag == -1)
    printf ("Given side inputs, can't be a triangle ");
    
  getch ();
}

Testing Result of the Program

Not a Triangle

 Enter the values of a, b and c : = 11 5 5
Given side inputs, can't be a triangle 

Equilateral triangle

Enter the values of a, b and c : = 4 4 4

It is an Equilateral Triangle

Isosceles Triangle

Enter the values of a, b and c : = 2 3 2

It is an isosceles Triangle

Difference between wait() and sleep() in Tabular form

wait() Method

Wait method makes a thread sleep and forces it to move to suspended state.

It also causes a thread to release its acquired lock.So that, other threads can get turn in order to perform their respective jobs.
A wait method always pair with a notify method. Both together provides a way of interthread communication.

Java program to demonstrate working of wait method ?

Program:

class WaitExample extends Thread
{
 @Override
 public void run() {
 print();
 }
 synchronized void print()
 {
 System.out.println("THis is child ");
 notify();
 }
}
public class Main {
 public static void main(String[] args) {
 WaitExample thread = new WaitExample();
 thread.start();
 synchronized (thread)
 {
 System.out.println("I am in synchronised :");
 try {
 thread.wait();
 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 System.out.println("I am in invoked :");
 }

Output:

sleep() Method

Sleep method puts a thread to sleep too but for specified  milliseconds.

It allows a thread to carry out its  remaining task once provided time ends. Unlike wait(), it doesn’t order a thread to release its locks until it completes its task.

Java program to demonstrate working of sleep method ?

Program:

class ThreadExample extends Thread{
    @Override
    public void run() {
        System.out.println("Child thread is about to sleep");
        try {
            sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("I am child Thread ");
    }
}
public class Main {

    public static void main(String[] args) {
ThreadExample thread1 = new ThreadExample();
thread1.start();
        System.out.println("I am Main Thread ");
    }
}

Output

Child thread is about to sleep

 I am Main Thread
 I am child Thread