# calculate dot product of two vectors implemented as lists
import math
def calcX(A,B):
    AdotB=0
    for i in range (len(A)):
       AdotB = AdotB + (A[i] * B[i])
    return AdotB

#check if two vectors are orthogonal
def orthogonal(A,B):
    if calcX(A,B) ==0:
        result = True
    else:
        result = False
    return result
#endsub

# normalise a vector 
def normalise (A):
    normalA = [0,0]
    print('normalA and A',normalA, '     ',A)
    length = math.sqrt(A[0]**2 + A[1]**2)
    print('length =',length)
    normalA[0] = round(A[0]/length,2)
    normalA[1] =round(A[1]/length,2)
    print('normalA',normalA, A)
    
    return normalA
#endsub

#main
A =[3,4]
B =[2,1]
x = calcX(A,B)
print('Dot product',x)
RightAngle = orthogonal(A,B)
print(RightAngle)
B = [2,-1.5]
RightAngle = orthogonal(A,B)
print('Right angle', RightAngle)
X = [3,4]
Y =  normalise(X)
print ('vector',X,'normalised is ',Y)