Python code:
from math import radians,cos,sin,asin,sqrt #Read the input from user print("Enter the latitute and longitude of two points on Earth in degrees.") lat1=float(input("Latitute 1:")) lat2=float(input("Latitute 2:")) lon1=float(input("Longitute 1:")) lon2=float(input("Longitute 2:")) #try and convert the string input to a number #tell the user off #The math module contains a function named radians which converts from degrees to radians. lat1=radians(lat1) lat2=radians(lat2) lon1=radians(lon1) lon2=radians(lon2) #Haversine formula dlon=lon2-lon1; dlat=lat2-lat1; a=sin(dlat/2)**2+cos(lat2)*sin(dlon/2)**2 c=2*asin(sqrt(a)) r=6300 # radius of earth in kilometers. print("Distance is:",c*r,"kilometers")