Design the test cases and test the program of Triangle problem by using Equivalence Class testing

You can check out the “Triangle problem” program along with its tested test cases here.

In triangle problem, we require to identify output and input domain.

Output Domain:

O₁ = Not a triangle, when any of the sides is greater than the sum of the other
O₂ = Equilateral Triangle
O₃ = Isosceles Triangle
O₄ = Scalene Triangle

Input Domain:
I₁ = { 0< a <= 10 }
I₂ = { a<0 }
I₃ = { a>10 }
I₄ = { 0< b <= 10 }
I₅= { b<0 }
I₆ = { b>10 }
I₇ = { 0< c <= 10 }
I₈ = { c<0 }
I₉ = { c>10 }

Further, on the basis of sides equality and whether the sum of the two sides are equal or greater, we can create classes.
I₁₀ = { a=b=c }
I₁₁ = { a=b, b!=c }
I₁₂ = { b=c, c!=a }
I₁₃ = { a=c, c!=b }
I₁₄ = { a!=b!=c }
I₁₅ = { a+b = c }
I₁₆ = { a+b < c }
I₁₇ = { b+c = a }
I₁₈ = { b+c < a }
I₁₉ = { c+a = b }
I₂₀ = { c+a >b }
There are 4 possible outcomes and 20 possible input classes, in total 24 test cases to test.

Here are the test cases and program tested results.