给定一个边长为 a 的等边三角形，任务是找到该等边三角形内切圆的面积。
例子：
Input : a = 4
Output : 4.1887902047863905
Input : a = 10
Output : 26.1799387799
方法：
Area of equilateral triangle =
Semi perimeter of equilateral triangle = (a + a + a) / 2
Radius of inscribed circle r = Area of equilateral triangle / Semi perimeter of equilateral triangle
=
=
Area of circle = PI*(r*r) =
下面是上述方法的实现：
C++
*** QuickLaTeX cannot compile formula:
*** Error message:
Error: Nothing to show, formula is empty
Java
*** QuickLaTeX cannot compile formula:
*** Error message:
Error: Nothing to show, formula is empty
Python3
*** QuickLaTeX cannot compile formula:
*** Error message:
Error: Nothing to show, formula is empty
C#
*** QuickLaTeX cannot compile formula:
*** Error message:
Error: Nothing to show, formula is empty
PHP
// C++ program to find the area
// of circle which is inscribed
// in equilateral triangle
# include
# define PI 3.14
using namespace std;
// Function return the area of circle
// inscribed in equilateral triangle
float circle_inscribed(int a)
{
return PI * (a * a) / 12;
}
// Driver code
int main()
{
int a = 4;
cout << circle_inscribed(a);
return 0;
}
// This code is contributed
// by Mahadev99 Javascript
// Java program to find the area
// of circle which is inscribed
// in equilateral triangle
import java.io.*;
class GFG
{
static double PI = 3.14;
// Function return the area of circle
// inscribed in equilateral triangle
static double circle_inscribed(int a)
{
return PI * (a * a) / 12;
}
// Driver code
public static void main (String[] args)
{
int a = 4;
System.out.println(circle_inscribed(a));
}
}
// This code is contributed by anuj_67输出：
# Python3 program to find the area of circle
# which is inscribed in equilateral triangle
# import math library for pi value
from math import pi
# Function return the area of circle
# inscribed in equilateral triangle
def circle_inscribed(a):
return pi*(a * a) / 12
# Driver code
a = 4
print(circle_inscribed(a))如果您希望与专家一起参加现场课程，请参阅DSA 现场工作专业课程和学生竞争性编程现场课程。