Kata

In this kata, you should calculate the type of triangle with three given sides a, b and c (given in any order).

If each angle is less than 90°, this triangle is acute and the function should return 1.

If one angle is strictly 90°, this triangle is right and the function should return 2.

If one angle is more than 90°, this triangle is obtuse and the function should return 3.

If three sides cannot form a triangle, or one angle is 180° (which turns the triangle into a segment) - the function should return 0.

Three input parameters are sides of given triangle. All input values are non-negative floating point or integer numbers (or both, depending on the language).

Acute

Right

Obtuse

Examples:

(2, 4, 6) ---> return 0 (Not triangle)
(8, 5, 7) ---> return 1 (Acute, angles are approx. 82°, 38° and 60°)
(3, 4, 5) ---> return 2 (Right, angles are approx. 37°, 53° and exactly 90°)
(7, 12, 8) ---> return 3 (Obtuse, angles are approx. 34°, 106° and 40°)

If you stuck, this can help you: http://en.wikipedia.org/wiki/Law_of_cosines. But you can solve this kata even without angle calculation.

There is a very small chance of random test to fail due to round-off error, in such case resubmit your solution.