public?static?void?trangle(double?a_x,double?a_y,double?b_x,double?b_y,double?c_x,double?c_y){
//Math.sqrt(x)表示開根號。Math.pow(x,n)表示x的n次方。
double?ab?=?Math.sqrt(Math.pow(a_x-b_x,?2)?+?Math.pow(a_y?-?b_y,?2));//直線ab
double?ac?=?Math.sqrt(Math.pow(a_x-c_x,?2)?+?Math.pow(a_y?-?c_y,?2));//直線bc
//求角B,C度數。Math.PI表示π;Math.atan2(x,?y)表示arctant(x/y),在Java中是弧線長度,因此要將長度轉換為度數。
double?B?=?Math.atan2(ac,?ab)*180/Math.PI;
double?C?=?Math.atan2(ab,?ac)*180/Math.PI;
System.out.println("B:"+B+"°\nC:"+C+"°");
}