我想在JavaScript中获得3点之间的夹角。如果我有点A(x1,y1),B(x2,y2),C(x3,y3),我想获得由AB和BC线形成的角度。
let A = {x:x1, y:y1}, B = {x:x2, y:y2}, C = {x:x3, y:y3}
尝试此功能:
/*
* Calculates the angle ABC (in radians)
*
* A first point, ex: {x: 0, y: 0}
* C second point
* B center point
*/
function find_angle(A,B,C) {
var AB = Math.sqrt(Math.pow(B.x-A.x,2)+ Math.pow(B.y-A.y,2));
var BC = Math.sqrt(Math.pow(B.x-C.x,2)+ Math.pow(B.y-C.y,2));
var AC = Math.sqrt(Math.pow(C.x-A.x,2)+ Math.pow(C.y-A.y,2));
return Math.acos((BC*BC+AB*AB-AC*AC)/(2*BC*AB));
}