Exercise #$2$: Redo exercise #$1$ but read the input $($Gross Amount$)$ from a file and write the output to a file.

Exercise#$3$: The sum of the interior angles of a triangle is $180$ degrees. Write a program that reads two interior angles of a triangle in degrees, and then calculates the third angle and print its value. The program should then print a message telling whether the triangle is:

Equilateral $($all angles equal$).$

Isoceles $($exactly two angles equal$)$

Scalene $($no two angles equal$).$