3. (9) Write a program to calculate the area of a triangle given the lengths of its three sides a, b, c, using Herons formula: A = sqrt( s(s a)(s b)(s c)) where s = (a + b + c)/2, the semi-perimeter Get the lengths of the sides from the user. Calculate the area of the triangle and output the area to the screen. Under certain circumstances, the lengths of three line segments do not form a triangle (i. e., the sum of any two sides must be greater than the third a + b > c, a + c > b and b + c > a). Revise the program to check that the line segments will form a triangle and if not, inform the user and ask for different lengths.