计算等边三角形面积和周长的程序

等边三角形是三条边和三个角都相等的三角形。等边三角形的三个内角都是60度。

等边三角形的面积：
• 如果我们知道等边三角形每边的长度，那么我们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和边长，那么我们可以使用下面提到的公式来计算它的面积。

  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

  面积公式是如何工作的？ 让我们看看下面的图表。我们知道三角形的高度是1/2*base*height。h的值是sqrt（a ^2. –（a/2） ^2. )=sqrt（3）*a/2。所以面积变成1/2*a*（sqrt（3）*a/2）=（sqrt（3）/4）*a*a

  例如：

  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
  

  推荐：请尝试你的方法 {IDE} 首先，在进入解决方案之前。

  C++

  // CPP program to find area // and perimeter of equilateral triangle #include <bits/stdc++.h> 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.

  PHP

  <?php // PHP program to find area // and perimeter of equilateral triangle // Function to calculate Area // of equilateral  triangle function area_equi_triangle( $side ) { return sqrt(3) / 4 * $side * $side ; } // Function to calculate Perimeter // of equilateral  triangle function peri_equi_triangle( $side ) { return 3 * $side ; } // Driver Code $side = 4; echo ( "Area of Equilateral Triangle: " ); echo (area_equi_triangle( $side )); echo ( "" ); echo ( "Perimeter of Equilateral Triangle: " ); echo ( peri_equi_triangle( $side )); // This code is contributed // by vt_m. ?>

  输出：

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