计算等边三角形面积和周长的程序

等边三角形是三个边和角度都相等的三角形。等边三角形的所有三个内角均为60度。

等边三角形的面积：
• 如果我们知道等边三角形各边的长度，则可以使用下面提到的公式来计算等边三角形的面积。

  Area of Equilateral Triangle = (sqrt(3)/4) * a * a    

• 如果我们知道等边三角形的高度长度以及边的长度，那么我们可以使用下面提到的公式来计算其面积。

  Area of Equilateral Triangle = (1/2) x Side x Altitude

  等边三角形的周长：

  Perimeter of Equilateral Triangle :  3 X a

  面积公式如何工作?
  让我们看下图。我们知道一个三角形是1/2 *基数*高度。 h的值是sqrt(a ² –(a / 2) ² )= sqrt(3)* a /2。因此，面积变为1/2 * a *(sqrt(3)* a / 2)=(sqrt (3)/ 4)* a * a
  

  例子 ：

  Input : side = 4
  Output : Area of Equilateral Triangle: 6.9282
           Perimeter of Equilateral Triangle: 12
  
  Input : side = 12
  Output : Area of Equilateral Triangle: 62.3538
           Perimeter of Equilateral Triangle: 36
  

  C++

  // CPP program to find area
  // and perimeter of equilateral triangle
  #include 
  using namespace std;
    
  // Function to calculate Area 
  // of equilateral triangle
  float area_equi_triangle(float side)
  {
      return sqrt(3) / 4 * side * side;
  }
    
  // Function to calculate Perimeter 
  // of equilateral triangle
  float peri_equi_triangle(float side)
  {
      return 3 * side;
  }
    
  // Driver Code
  int main()
  {
      float side = 4;
      cout << "Area of Equilateral Triangle: "
           << area_equi_triangle(side) << endl;
      cout << "Perimeter of Equilateral Triangle: "
           << peri_equi_triangle(side);
      return 0;
  }

  Java

  // Java Program to find area and
  // perimeter of equilateral triangle
  import java.io.*;
    
  class GFG 
  {
      // Function to calculate 
      // Area of equilateral triangle
      static float area_equi_triangle(float side)
      {
    
          return (float)(((Math.sqrt(3)) / 4) *
                           side * side);
      }
    
      // Function to calculate 
      // Perimeter of equilateral
      // triangle
      static float peri_equi_triangle(float side)
      {
          return 3 * side;
      }
        
      // Driver Code
      public static void main(String arg[])
      {
          float side = 4;
          System.out.print("Area of Equilateral Triangle:");
          System.out.println(area_equi_triangle(side));
          System.out.print("Perimeter of Equilateral Triangle:");
          System.out.println(peri_equi_triangle(side));
      }
  }
    
  // This code is contributed 
  // by Anant Agarwal.

  Python

  # Python3 program to calculate Area and 
  # Perimeter of equilateral Triangle
    
  # Importing Math library for sqrt
  from math import *
    
  # Function to calculate Area 
  # of equilateral triangle
  def area_equilateral( side ):
      area = (sqrt(3) / 4) * side * side
      print ("Area of Equilateral Triangle: % f"% area)
    
  # Function to calculate Perimeter
  # of equilateral triangle 
  def perimeter( side ):
      perimeter = 3 * side
      print ("Perimeter of Equilateral Triangle: % f"% perimeter)
        
  # Driver code
  side = 4
  area_equilateral( side )
  perimeter( side )

  C#

  // C# Program to find area and
  // perimeter of equilateral triangle
  using System;
    
  class GFG 
  {
      // Function to calculate 
      // Area of equilateral triangle
      static float area_equi_triangle(float side)
      {
    
          return (float)(((Math.Sqrt(3)) / 4) * 
                           side * side);
      }
    
      // Function to calculate 
      // Perimeter of equilateral
      // triangle
      static float peri_equi_triangle(float side)
      {
          return 3 * side;
      }
        
      // Driver Code
      public static void Main()
      {
          float side = 4;
          Console.Write("Area of Equilateral Triangle:");
          Console.WriteLine(area_equi_triangle(side));
          Console.Write("Perimeter of Equilateral Triangle:");
          Console.WriteLine(peri_equi_triangle(side));
      }
  }
    
  // This code is contributed 
  // by vt_m.

  输出 ：

  Area of Equilateral Triangle: 6.9282
  Perimeter of Equilateral Triangle: 12