正方形内的叶子面积

给定整数a作为正方形ABCD的边。任务是在正方形内找到叶子AECFA的面积，如下所示：

例子：

Input: a = 7
Output: 28

Input: a = 21
Output: 252

方法：要计算叶子的面积，首先要找到半叶子AECA的面积，可以将其表示为：

Area of half leaf = Area of quadrant AECDA – Area of right triangle ACD.
Thus, Area of half leaf = ( PI * a * a / 4 ) – a * a / 2 where PI = 22 / 7 and a is the side of the square.
Hence, the area of full leaf will be ( PI * a * a / 2 ) – a * a
On taking a * a common we get, Area of leaf = a * a ( PI / 2 – 1 )

下面是上述方法的实现：

C

// C program to find the area of
// leaf inside a square
#include 
#define PI 3.14159265
  
// Function to find area of
// leaf
float area_leaf(float a)
{
    return (a * a * (PI / 2 - 1));
}
  
// Driver code
int main()
{
    float a = 7;
    printf("%f",
           area_leaf(a));
    return 0;
}

Java

// Java code to find the area of
// leaf inside a square
import java.lang.*;
  
class GFG {
  
    static double PI = 3.14159265;
  
    // Function to find the area of
    // leaf
    public static double area_leaf(double a)
    {
        return (a * a * (PI / 2 - 1));
    }
  
    // Driver code
    public static void main(String[] args)
    {
        double a = 7;
        System.out.println(area_leaf(a));
    }
}

Python3

# Python3 code to find the area of leaf 
# inside a square
PI = 3.14159265
      
# Function to find the area of 
# leaf
def area_leaf( a ):
    return ( a * a * ( PI / 2 - 1 ) )
      
# Driver code
a = 7
print(area_leaf( a ))

C#

// C# code to find the area of
// leaf
// inside square
using System;
  
class GFG {
    static double PI = 3.14159265;
  
    // Function to find the area of
    // leaf
    public static double area_leaf(double a)
    {
        return (a * a * (PI / 2 - 1));
    }
  
    // Driver code
    public static void Main()
    {
        double a = 7;
        Console.Write(area_leaf(a));
    }
}

输出：

28