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📜  圆心与两个横向公切线与圆的交点之间的距离之比

📅  最后修改于: 2021-04-27 22:23:18             🧑  作者: Mango

给定半径的两个圆,使两个圆彼此不接触。任务是找到圆心与两个横向公切线与圆的交点的距离之比。
例子:

Input :r1 = 4, r2 = 8 
Output :1:2

Input :r1 = 5, r2 = 13
Output :5:13

方法

  • 令圆的半径分别为r1r2C1C2
  • P为两个横向公切线与圆的交点,而A1A2为切线与圆的接触点。
  • 在三角形PC1A1和三角形PC2A2中
    C1A1P =角C2A2P = 90度{将圆心与接触点连接的线与切线成90度角},
    同样,角度A1PC1 =角度A2PC2 {垂直相反的角度始终相等}
    因此,角度A1C1P =角度A2C2P
    因为角度相同,所以三角形PC1A1PC2A2相似。
  • 因此,由于三角形的相似性,
    C1P / C2P = C1A1 / C2A2 = r1 / r2

The ratio of the distance between the centres of the circles and the point of intersection of two transverse common tangents to the circles = radius of the first circle/radius of the second circle

C++
// C++ program to find the ratio
// of the distance between the centres of the circles
// and the point of intersection
// of two transverse common tangents
// to the circles which do not touch each other
 
#include 
using namespace std;
 
int GCD(int a, int b)
{
    return (b != 0 ? GCD(b, a % b) : a);
}
 
// Function to find the ratio
void ratiotang(int r1, int r2)
{
    cout << "The ratio is "
         << r1 / GCD(r1, r2)
         << ":"
         << r2 / GCD(r1, r2)
         << endl;
}
 
// Driver code
int main()
{
    int r1 = 4, r2 = 8;
    ratiotang(r1, r2);
    return 0;
}


Java
// Java program to find the ratio
// of the distance between the centres of the circles
// and the point of intersection
// of two transverse common tangents
// to the circles which do not touch each other
 
import java.io.*;
 
class GFG{
 
    static int GCD(int a, int b)
    {
        return (b != 0 ? GCD(b, a % b) : a);
    }
 
    // Function to find the ratio
    static void ratiotang(int r1, int r2)
    {
        System.out.println("The ratio is "
            + r1 / GCD(r1, r2)
            + ":"
            + r2 / GCD(r1, r2));
    }
 
    // Driver code
    public static void main (String[] args)
    {
        int r1 = 4, r2 = 8;
        ratiotang(r1, r2);
    }
}
 
// This code is contributed by NamrataSrivastava1


Python
# Python3 program to find the ratio
# of the distance between the centres of the circles
# and the point of intersection
# of two transverse common tangents
# to the circles which do not touch each other
 
def GCD(a, b):
    if(b!=0):
        return GCD(b, a%b);
    else:
        return a;
 
# Function to find the ratio
def ratiotang(r1, r2):
 
    print("The ratio is", r1 // GCD(r1, r2),
                     ":", r2 // GCD(r1, r2));
 
# Driver code
r1 = 4; r2 = 8;
ratiotang(r1, r2);
 
# This code is contributed by Code_Mech


C#
// C# program to find the ratio
// of the distance between the centres of the circles
// and the point of intersection
// of two transverse common tangents
// to the circles which do not touch each other
using System;
 
class GFG
{
 
    static int GCD(int a, int b)
    {
        return (b != 0 ? GCD(b, a % b) : a);
    }
 
    // Function to find the ratio
    static void ratiotang(int r1, int r2)
    {
        Console.WriteLine("The ratio is "
            + r1 / GCD(r1, r2)
            + ":"
            + r2 / GCD(r1, r2));
    }
 
    // Driver code
    static public void Main ()
    {
         
        int r1 = 4, r2 = 8;
        ratiotang(r1, r2);
    }
}
 
// This code is contributed by Tushil.


PHP


Javascript


输出:
The ratio is 1:2