In this post, we will study the test cases for a triangle. This question is usually asked in manual testing interviews, in which the interviewer wants to check if you can think of the different test scenarios of a common object like a triangle.
In order to answer these type of questions, basically, we will validate the different requirements which are nothing but the different properties of a triangle.
- Verify that the figure is closed (polygon).
- Verify that the figure is two-dimensional and formed with straight lines only.
- Verify that the figure has exactly three sides.
- Verify that the figure has exactly three vertices.
- Verify that the figure has exactly three angles.
- Verify that the sum of the angles of the figure is 180 degrees.
- Verify that no two sides are parallel to each other.
- Verify that the sum of the length of two sides of the triangle should be greater than the length of the third side.
- Verify that no two angles of a triangle have 90 degrees and above value.
- Verify the type of traingle is as per the specification, based on its sides – scalene, isosceles or equilateral.
- Verify the type of triangle is as per the specification, based on its angles – acute angle, obtuse angle, or right-angled triangle.
- Verify that the area of triangle is equal to half of the product of its base and height.
Test Case Examples

Kuldeep is the founder and lead author of ArtOfTesting. He is skilled in test automation, performance testing, big data, and CI-CD. He brings his decade of experience to his current role where he is dedicated to educating the QA professionals. You can connect with him on LinkedIn.
Nice Article…. Helped me a lot. Thanks for all important questions.