# Procedure

h1.

## Compute hypotenuse with validation

Body:

Compute the hypotenuse of a right angled triangle, with input validation.

(If you were logged in as a student, you could submit an exercise solution, and get some feedback.)

# DRY

DRY stands for Don't Repeat Yourself. One of the Big Ideas of programming.

Big Idea

Don't repeat yourself

Write similar code once. Put it in a Sub. Use params to tell the Sub what to do differently each time the Sub is called.

So far, each of the subs has been called just once per program. Let's do something different.

# Retaxing

Remember that strange tax return program? The worksheet: