已知直角三角形两点坐标,求第三点,任意三点坐标求三角形面积

void Calculate(Vector2 p1, Vector2 p2, Vector2 p3) { float a = Vector2.Distance(p2, p3); float b = Vector2.Distance(p1, p3); float c = Vector2.Distance(p1, p2); Debug.Log(a + " " + b + " " + c); float angleA = Mathf.Acos((b * b + xsdqc) / (2 * b * c)) * Mathf.Rad2Deg; float angleB = Mathf.Acos((a * a + c * c - b * b) / (2 * a * c)) * Mathf.Rad2Deg; float angleC = Mathf.Acos((a * a + b * b - c * c) / (2 * a * b)) * Mathf.Rad2Deg; Debug.Log(angleA + " " + angleB + " " + angleC); }

推到过程

已知 : A(1,0),B(4,6),C(−3,5) 三点

根据距离公式：d=

先算数三条边长 a b c

a=√(4+3)2+(6−5)2=√50

b=√(1+3)2+(0−5)2=√41

c=√(1−4)2+(0−6)2=√45

根据cos公式得到