# The course is catching illegal input of

The Classic Triangle Testing Problem, (Myer’s Triangle): A program reads

three integer values. The three values are interpreted as representing the

lengths of the sides of a triangle. The program prints a message that states

whether the triangle is scalene, isosceles, or equilateral. Develop a set of

test cases (at least 6 ) that you feel will adequately test this program.

(This is a classic testing problem and you could find numerous explanations

about it on the internet. I would recommend that you try to submit your own

answer, based on your understanding of the topic)

Let’s define what the

three different types of triangle requirements for the side’s lengths are:

A scalene triangle is a

triangle with three sides having different lengths.

An isosceles triangle is

a triangle with two sides having equal lengths.

An equilateral triangle

is a triangle with all three sides of equal lengths.

The triangle inequality

Theorem states that the sum of 2 sides has to greater than the third side (Triangle inequality thereom rule explaned, nd).

The first test of course

is catching illegal input of a negative number being entered and the program

should catch that as not being allowed and rejected it requesting a positive

number informing the user that no negative numbers are allowed.

The second test case

scenario is catching the user entering non numbers and inform the user only

numbers are accepted as valid input and not symbols or alphabetical letters.

The third test case

scenario is catching that zero is not allowed as a value being entered and

informs the user to input a valid positive number that is bigger than zero.

The fourth case test

scenarios is checking that the 3 values entered that are valid indeed makes a

valid triangle by having the sum of two sides being greater than the third and

display an error message informing the user that the values entered don’t make

a valid triangle.

The fifth test case

scenario is when 3 valid but equal values are entered that it appropriately

display the message that it is an equilateral triangle.

The sixth test case

scenario is when 3 valid and different values are entered that it recognizes

that it is a scalene triangle and display the message accordingly.

The seventh test case

scenario is when 2 sides entered are of equal value that it informs the user

that it is indeed an isosceles triangle with 2 sides having equal length.

I

believe with these seven test cases, most user input errors are caught and

values are check to see if they make a valid triangle and then display what

type they are adequately giving us a program that will function as per

requested requirements given of the three triangle types.

References

Triangle inequality thereom rule explaned. (nd). Retrieved from Math Warehouse:

http://www.mathwarehouse.com/geometry/triangles/triangle-inequality-theorem-rule-explained.php