Write a well$-$documented $($commented$)$ program to calculate the area of a triangle given the length of its three sides a$,$ b$,$ and c$,$ using the following formulas:

$,$ where A is the area of the triangle

The program should prompt the user for the length of the three sides of the triangle and then print its area.

Submit your program as a script file named $$COS$-205\_$assignment$2$a$\_.$py$.$

Part B

Write a well$-$documented $($commented$)$ program to find the sum of the first n natural numbers. The program should prompt the user for the value of n$,$ and then print the sum.

Submit your program as a script file named $.$py