A circle is a round shape two-dimensional diagram which has no corners. Every circle has an origin point and every point on the circle maintains equal distance from the origin. The distance between the origin and a point in a circle is known as Radius of the circle. And similarly, if we draw a line from one edge to another edge of the circle and the origin is held in the middle of it, that line is known as diameter of the circle. Basically, the diameter is double of the length of the radius.
A square consists of four sides and all the four sides have equal length. If we try to put a circle inside a square with maximum radius possible, then the diameter of the circle is equal to the length of the side of the square. So here we can conclude that the radius of the circle is equal to half of the square’s side length.
Area of the circle refers to the total surface area acquired by the circle. We can calculate the square of the circle by using radius and a constant known as π
Formula to calculate area of the circle −
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$$\mathrm{面积=\pi \times (半径)^{2}}$$
由于圆被内接在一个正方形中，所以圆的半径（r）= 边长/2，其中‘边长’指的是正方形的边长。
$$\mathrm{Area \;of \; inscribed \;circle \;in \;square=\varpi\times(side/2)^{2}=\varpi\times(side^{2}/4)=(\varpi/4)^{*}sides^{2}}$$
在本文中，我们将看到如何找到内接在正方形中的圆的面积
using Java.To show you some instances −
Instance-1
The side length of the square given = 9 The area of the circle inscribed in square = (ϖ / 4) * side2 = (3.141/4) * 9 * 9 = 63.605
Instance-2
The side length of the square given = 50 The area of the circle inscribed in square = (ϖ / 4) * side2 = (3.141/4) * 50 * 50 = 1963.125
Instance-3
The side length of the square given = 32 The area of the circle inscribed in square = (ϖ / 4) * side2 = (3.141/4) * 32 * 32 = 804.096
Algorithm
Step-1 − Get the side length of the square either by static input or by user input.
Step-2 − Find the area of the circle inscribed in a square by using the formula.
Step-3 − Print the result.
Multiple Approaches
我们以不同的方法提供了解决方案。
By Using Static Input Value.
通过使用具有静态输入值的用户定义方法。
通过使用用户定义的方法和用户输入的值。
Let’s see the program along with its output one by one.
途径-1：通过使用静态输入值
在这种方法中，我们声明一个双精度变量，并将其初始化为正方形的边长。然后通过使用算法，我们可以找到内切于正方形的圆的面积。
Example
import java.io.*;
public class Main {
//main method
public static void main (String[] args) {
//declare a variable to store the value of pi
double pi = 3.14;
//declare a variable to store the value of side of the square
float side = 15;
//declare a variable to store the area of the circle
//find area by using the formula
double area = ( pi / 4 ) * side * side;
System.out.println("Area of the circle inscribed in the square is: "+ area);
}
}
Output
Area of the circle inscribed in the square is: 176.625
Approach-2: By Using User Defined Method with Static Input Value
In this approach, we declare a double variable and initialize the side length value of the square. Then by using the algorithm we can find the area of the circle inscribed in a square.
Example
import java.io.*;
public class Main {
//declare a static variable to store the value of pi
static double pi = 3.14;
//main method
public static void main (String[] args) {
//declare a variable to store the value of side of the square
float side = 15;
System.out.println("Area of the circle inscribed in the square is: "+ areaOfCircle(side));
}
// user-defined method to find the area of the circle
static double areaOfCircle(float side) {
return ( pi / 4 ) * side * side;
}
}
Output
Area of the circle inscribed in the square is: 176.625
Approach-3: By Using User Defined Method with User Input Value
在这种方法中，我们声明一个双精度变量，并获取用户输入的正方形的边长。然后通过使用算法，我们可以找到内切于正方形的圆的面积。
Example
import java.io.*;
import java.util.*;
public class Main {
//declare a static variable to store the value of pi
static double pi = 3.14;
//main method
public static void main (String[] args) {
//Create object of Scanner class
Scanner sc= new Scanner(System.in);
System.out.print("Enter the length of side of the square: ");
//declare a variable to store the value of side of the square
double side = sc.nextDouble();
System.out.println("Area of the circle inscribed in the square is: "+
areaOfCircle(side));
}
// user-defined method to find the area of the circle
static double areaOfCircle(double side) {
return ( pi / 4 ) * side * side;
}
}
Output
Enter the length of side of the square: 9 Area of the circle inscribed in the square is: 63.585
In this article, we explored how to find the area of a circle inscribed in a square in Java by using different approaches.
