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è§ä¹å为 180度ã
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代ç å¦ä¸ï¼
//Scanner sc = new Scanner(System.in);
//System.out.print("请è¾å
¥åæ ï¼");
double x1,y1,x2,y2,x3,y3;
x1 = 7; //sc.nextDouble();
y1 = 1; //sc.nextDouble();
x2 = 1; //sc.nextDouble();
y2 = 11; //sc.nextDouble();
x3 = 13; //sc.nextDouble();
y3 = 11; //sc.nextDouble();
double a,b,c;
a = Math.sqrt(Math.pow((x1-x2),2)+Math.pow((y1-y2),2));
b = Math.sqrt(Math.pow((x1-x3),2)+Math.pow((y1-y3),2));
c = Math.sqrt(Math.pow((x3-x2),2)+Math.pow((y3-y2),2));
double cosa,cosb,cosc;
cosa = (b*b+c*c-a*a)/(2*b*c);
cosb = (a*a+c*c-b*b)/(2*a*c);
cosc = (a*a+b*b-c*c)/(2*a*b);
System.out.println("aè§åº¦:"+Math.toDegrees(Math.acos(cosa)));
System.out.println("bè§åº¦:"+Math.toDegrees(Math.acos(cosb)));
System.out.println("cè§åº¦:"+Math.toDegrees(Math.acos(cosc)));
è¾åºå¦ä¸ï¼