循环领域

圆形扇区或圆形扇区是磁盘的两个半径和弧线所包围的部分，其中较小的区域称为次要扇区，较大的区域称为主扇区。让我们看一下这个图并尝试找出该扇区：

资料来源：维基百科(https://goo.gl/mWijn2)

在此图中，绿色阴影部分是一个扇形，“ r”是半径，“ theta”是角度，如图所示。在这里，我们可以说阴影部分是次要部分，其他部分是主要部分。 “ L”是扇形的弧线。有关更多信息，请访问部门。
现在让我们看一下可以用来计算圆的扇形的公式。

扇形的面积类似于圆的面积的计算，只是将圆的面积乘以扇形的角度即可。
例子：

Input:
radius = 9
angle = 60
Explanation:
Sector = ( pi * 9*9 ) * ( 60 / 360 )
Output: 42.42857142857142

Input:
radius = 20
angle = 145
Explanation:
Sector = ( pi * 20*20 ) * ( 145 / 360 )
Output: 506.3492063492063

C++

// C++ program to find Area of a Sector
#include 
using namespace std;
  
void SectorArea(double radius,double angle)
{
    if(angle >= 360)
        cout<<"Angle not possible";
      
    // Calculating area of the sector
    else
    {
        double sector = ((22 * radius * radius) / 7) 
                       * (angle / 360);
        cout<

---

Java

// Java program to find Area of a Sector
  
class GFG 
{
    static void SectorArea(double radius,double angle)
    {
        if(angle >= 360)
            System.out.println("Angle not possible");
          
        // Calculating area of the sector
        else
        {
            double sector =((22 * radius * radius) / 7) 
                           * (angle / 360);
            System.out.println(sector);
        }
    }
      
    // Driver code
    public static void main (String[] args)
    {
        double radius = 9;
        double angle = 60;
        SectorArea(radius, angle);
    }
}
// This code is contributed by Anant Agarwal.

Python3

# Python program to find Area of a Sector
  
def SectorArea(radius, angle):
    pi = 22 / 7
      
    # Constraint or Limit
    if angle >= 360:
        print("Angle not possible")
        return
      
    # Calculating area of the sector
    else:
        sector = (pi * radius ** 2) * (angle / 360)
        print(sector)
        return
  
# Driver code 
radius = 9
angle = 60
SectorArea(radius, angle)

C#

// C# program to find Area of a Sector
using System;
  
class GFG {
      
    static void SectorArea(double radius, double angle)
    {
          
        if (angle >= 360)
            Console.WriteLine("Angle not possible");
  
        // Calculating area of the sector
        else {
            double sector = ((22 * radius * radius) / 7)
                            * (angle / 360);
                              
            Console.WriteLine(sector);
        }
    }
  
    // Driver code
    public static void Main()
    {
        double radius = 9;
        double angle = 60;
          
        SectorArea(radius, angle);
    }
}
  
// This code is contributed by vt_m.

PHP

= 360)
        echo("Angle not possible");
      
    // Calculating area of the sector
    else
    {
        $sector = ((22 * $radius * $radius)
                     / 7) * ($angle / 360);
        echo($sector);
    }
} 
  
// Driver code
  
    $radius = 9;
    $angle = 60;
    SectorArea($radius, $angle);
      
// This code is contributed by vt_m.
?>

输出：

42.42857142857142

参考：维基百科(循环部门)