import point
import math

class Triangle:
    pass

def create(p1, p2, p3):
    tri = Triangle()
    tri.p1 = point.clone(p1)
    tri.p2 = point.clone(p2)
    tri.p3 = point.clone(p3)
    return tri

def area(tri):
    a = point.distance(tri.p1, tri.p2)
    b = point.distance(tri.p1, tri.p3)
    c = point.distance(tri.p2, tri.p3)
    return math.sqrt((a+b-c) * (a-b+c) * (-a+b+c) * (a+b+c))/4