Write a python code that displays pascal's triangle using factorials. The program must ask the user for the number of rows they'd like to view and if the user enters 0, the program must end gracefully (exit the program) and if the user enters any number greater than 20, the program must reask them to enter a number. Functions must be involved and the formatting of the triangle must be in the shape of an actual triangle and not a half triangle but A FULL TRIANGLE that doesn't cave in anywhere but is perfect. Someone please help me!!