from math import *

def magnitude(x1, y1, x2, y2):
    return sqrt((x2-x1)**2 + (y2-y1)**2)

def area3(x1, y1, x2, y2, x3, y3):
    magnitude(x1,y1,x2,y2)
    return a
    magnitude(x2,y2,x3,y3)
    return b
    magnitude(x3,y3,x1,y1)
    return c
    herons_formula(a,b,c)
    return herons_formula(a,b,c)



# Don't need to modify the following function
def herons_formula(a, b, c):
    s = (a + b + c) / 2
    return sqrt(s * (s - a) * (s - b) * (s - c))