先計算兩個線段的弧度 再乘以180/π 得到兩個點到中間點的夾角角度
function getAngle(pointA, pointB, pointC) {
const ABX = pointA.longitude - pointB.longitude; const ABY = pointA.latitude - pointB.latitude; const CBX = pointC.longitude - pointB.longitude; const CBY = pointC.latitude - pointB.latitude; const AB_MUL_CB = ABX * CBX + ABY * CBY; const DIST_AB = Math.sqrt(ABX*ABX+ABY*ABY) const DIST_CB = Math.sqrt(CBX*CBX+CBY*CBY) const cosValue = AB_MUL_CB/(DIST_AB*DIST_CB); return Math.acos(cosValue)*180/Math.PI; } //90度 console.log(getAngle({longitude:116.379817,latitude:39.930138},{longitude:116.3805,latitude:39.91333},{longitude:116.398035,latitude:39.913856}))