from math import sqrt
x1 = 0
x2 = 0
x3 = 1.73205
x4 = 1.73205
y1 = 2
y2 = 0
y3 = 1
y4 = 2

print "---------------------------------------------"
#method 1
AreaMethod1 = ((x1*y2-x2*y1)+(x2*y3 - x3*y2)+(x3*y4 - x4*y3)+(x4*y1 - x1*y4))*(0.5)
print "Area of quadrilateral by method 1 is " + str(AreaMethod1)

#method 2
print "---------------------------------------------"
sidea = sqrt((x2-x1)**2+(y2-y1)**2)
sideb = sqrt((x3-x2)**2+(y3-y2)**2)
sidec = sqrt((x3-x1)**2+(y3-y1)**2)
sided = sqrt((x4-x3)**2+(y4-y3)**2)
sidee = sqrt((x4-x1)**2+(y4-y1)**2)

HalfPerimeterTriangle1 = (sidea + sideb + sidec)*(0.5)
HalfPerimeterTriangle2 = (sidec + sided + sidee)*(0.5)

AreaTriangle1 = sqrt(HalfPerimeterTriangle1*(HalfPerimeterTriangle1-sidea)*(HalfPerimeterTriangle1-sideb)*(HalfPerimeterTriangle1-sidec))
AreaTriangle2 = sqrt(HalfPerimeterTriangle2*(HalfPerimeterTriangle2-sidec)*(HalfPerimeterTriangle2-sided)*(HalfPerimeterTriangle2-sidee))

AreaMethod2 = AreaTriangle1 + AreaTriangle2
print "Area of quadrilateral by method 2 is " + str(AreaMethod2)

#method 3
print "---------------------------------------------"
sidec = sqrt((x4-x2)**2+(y4-y2)**2)

HalfPerimeterTriangle1 = (sidea + sidee + sidec)*(0.5)
HalfPerimeterTriangle2 = (sideb + sided + sidec)*(0.5)

AreaTriangle1 = sqrt(HalfPerimeterTriangle1*(HalfPerimeterTriangle1-sidea)*(HalfPerimeterTriangle1-sidee)*(HalfPerimeterTriangle1-sidec))
AreaTriangle2 = sqrt(HalfPerimeterTriangle2*(HalfPerimeterTriangle2-sideb)*(HalfPerimeterTriangle2-sided)*(HalfPerimeterTriangle2-sidec))

AreaMethod3 = AreaTriangle1 + AreaTriangle2
print "Area of quadrilateral by method 3 is " + str(AreaMethod3)
print "---------------------------------------------"