叉积求面积

解题思路:

注意事项:

参考代码:

def Cross(x1,y1,x2,y2):
   return x1*y2-y1*x2
x1,y1,x2,y2,x3,y3=map(float,input().split())
a1=x1-x2
a2=y1-y2
b1=x1-x3
b2=y1-y3
triangle=abs(Cross(a1,a2,b1,b2))/2
print("%.2f" %triangle)