This answer quotes ChatGPT
Given the three coordinates and their distance from the fourth coordinate, the position of the fourth coordinate can be calculated using the triangular positioning method. This method is based on the Pythagorean theorem. The fourth coordinate can be determined by calculating the length and Angle of the three sides of a triangle.
Specifically, here are the steps to calculate the fourth coordinate:
1. Calculate the sides of a triangle according to the given three coordinates. Let the three coordinates be A(x1, y1, z1), B(x2, y2, z2), and C(x3, y3, z3), then the three sides are AB, AC, and BC. The calculation formula is as follows:
AB = sqrt((x2 - x1)^2 + (y2 - y1)^2 + (z2 - z1)^2)
AC = sqrt((x3 - x1)^2 + (y3 - y1)^2 + (z3 - z1)^2)
BC = sqrt((x3 - x2)^2 + (y3 - y2)^2 + (z3 - z2)^2)
2. According to the Pythagorean theorem, three angles of a triangle can be calculated. Suppose that the three inner angles of A triangle are Angle a, Angle B and Angle C, and the corresponding side lengths are A, b and c, then the calculation formula is as follows:
cosA = (b^2 + c^2 - a^2) / (2bc)
cosB = (a^2 + c^2 - b^2) / (2ac)
cosC = (a^2 + b^2 - c^2) / (2ab)
Where, cosA, cosB and cosC represent the cosine values of the three angles respectively. Cosine values can be converted to angular values by an inverse cosine function such as the acos function.
3. Determine the distance between the fourth coordinate and the three known coordinates. Assuming the fourth coordinate is D(x4, y4, z4), the lengths of AD, BD, and CD can be calculated separately from the known distances. Let them be d1, d2 and d3, then the formula is as follows:
d1 = sqrt((x4 - x1)^2 + (y4 - y1)^2 + (z4 - z1)^2)
d2 = sqrt((x4 - x2)^2 + (y4 - y2)^2 + (z4 - z2)^2)
d3 = sqrt((x4 - x3)^2 + (y4 - y3)^2 + (z4 - z3)^2)
4. According to the sine theorem of triangles, the corresponding sine value of each Angle in a triangle can be calculated. Suppose that the sine values corresponding to Angle A, B and C are sinA, sinB and sinC respectively, then the calculation formula is as follows:
sinA = sqrt(1 - cosA^2)
sinB = sqrt(1 - cosB^2)
sinC = sqrt(1 - cosC^2)
5. Finally, the position of the fourth coordinate can be calculated according to the definition of trigonometric functions and the Pythagorean theorem. Specifically, it can be calculated by the following formula:
x4 =(d1 * sinA *(y3 - y1) + d2 * sinB *(y3 - y2) + d3 * sinC *(y2 - y1)) /(2 *(sinA *(x3 - x1) + sinB *(x3 - x2) + sinC *(x2 - x1)))
y4 =(d1 * sinA *(x3 - x1) + d2 * sinB *(x3 - x2) + d3 * sinC *(x2 - x1)) /(2 *(sinA *(y3 - y1) + sinB *(y3 - y2) + sinC *(y2 - y1)))
z4 = sqrt(r^2 - x4^2 - y4^2)
where r represents the distance between the fourth coordinate and the three known coordinates. The basic idea of this formula is to use the Pythagorean theorem to calculate the three angles of a triangle, and then use trigonometric functions to calculate the position of the fourth coordinate in three-dimensional space.
Note that this formula only works if three coordinates are known and their distance from the fourth coordinate is equal. If only part of the distance is known, or if the distance is not equal, you need to use other methods to calculate the position of the fourth coordinate.
Here is sample code for calculating the fourth coordinate using C# given three coordinates and their distance from the fourth coordinate:
using System;
class Program
{
static void Main(string[] args)
{
// 三个已知坐标和它们到第四个坐标的距离
double x1 = 0, y1 = 0, z1 = 0, d1 = 2;
double x2 = 3, y2 = 0, z2 = 0, d2 = 3;
double x3 = 0, y3 = 4, z3 = 0, d3 = 4;
// 计算三边长
double AB = Math.Sqrt(Math.Pow(x2 - x1, 2) + Math.Pow(y2 - y1, 2) + Math.Pow(z2 - z1, 2));
double AC = Math.Sqrt(Math.Pow(x3 - x1, 2) + Math.Pow(y3 - y1, 2) + Math.Pow(z3 - z1, 2));
double BC = Math.Sqrt(Math.Pow(x3 - x2, 2) + Math.Pow(y3 - y2, 2) + Math.Pow(z3 - z2, 2));
// 计算三个角的余弦值
double cosA = (Math.Pow(BC, 2) + Math.Pow(AB, 2) - Math.Pow(AC, 2)) / (2 * BC * AB);
double cosB = (Math.Pow(AC, 2) + Math.Pow(BC, 2) - Math.Pow(AB, 2)) / (2 * AC * BC);
double cosC = (Math.Pow(AB, 2) + Math.Pow(AC, 2) - Math.Pow(BC, 2)) / (2 * AB * AC);
// 将余弦值转换为角度值
double radA = Math.Acos(cosA);
double radB = Math.Acos(cosB);
double radC = Math.Acos(cosC);
// 计算每个角对应的正弦值
double sinA = Math.Sin(radA);
double sinB = Math.Sin(radB);
double sinC = Math.Sin(radC);
// 计算第四个坐标的位置
double x4 = (d1 * sinA * (y3 - y1) + d2 * sinB * (y3 - y2) + d3 * sinC * (y2 - y1)) / (2 * (sinA * (x3 - x1) + sinB * (x3 - x2) + sinC * (x2 - x1)));
double y4 = (d1 * sinA * (x3 - x1) + d2 * sinB * (x3 - x2) + d3 * sinC * (x2 - x1)) / (2 * (sinA * (y3 - y1) + sinB * (y3 - y2) + sinC * (y2 - y1)));
double z4 = Math.Sqrt(Math.Pow(d1, 2) - Math.Pow(x4, 2) - Math.Pow(y4, 2));
Console.WriteLine("第四个坐标为:({0}, {1}, {z4})", x4, y4, z4);
In the code, we first define the three known coordinates and their distance from the fourth coordinate. Then, the Pythagorean theorem is used to calculate the length of the three sides of the triangle, and then calculate the cosine of the three angles. The cosine value is converted to the Angle value by the inverse cosine function, and then the sine value corresponding to each Angle is calculated.
Finally, the position of the fourth coordinate is calculated according to the formula of triangle positioning method, and the result is output. The Math.Sqrt function is used to compute the square root, and the Math.Pow function is used to compute the specified power of the specified number.