Thanks Roy that’s useful. I shall copy that and save it. The whole code is as shown below just to give you the whole flavour. It works. Ijust want to improve using list comprehension. I tried what you suggested butit did not work. Excuse the amateurishness. I intend to upload this together with the normal calculation if that’s OK with you

print(’’’ This is a code for calculating the area of a parallelogram given three coordinates’’’)

print (’’‘you may get a negative answer depending on whiich coords you choose first’’’)

print (’’‘Please enter your first x coordinate, then press enter, then your second x coordinate, press

enter then your third x cordinate. Then repeat for your y coordinates and then a final enter’’’)

x=[]

for i in range (3): # 3 because we need three x coordinates

x.append (int(input())) # stores your x coordinates

y=[]

for j in range (3): # 3 because we need the three equivalent/corresponding y coordinates

y.append(int(input())) # stores your y coordinates

x.append(x[0]) #appends the first x coordinate to the end

y.append(y[0]) #appends the first ycoordinate to the end

print (x)

print (y)

a=x[0]*y[1]+x[1]*y[2] +x[2]*y[3] #cross/diagonally multiplying x and y coordinate from left to right

print (a)

b =x[3]*y[2]+x[2]*y[1] +x[1]*y[0] #cross/diagonally multiplying x and y coordinate from right to left

print(b)

c= a - b

print(" area = “, c, " square units”)