# Triangle

Determine if a triangle is equilateral, isosceles, or scalene.

An _equilateral_ triangle has all three sides the same length.

An _isosceles_ triangle has at least two sides the same length. (It is sometimes
specified as having exactly two sides the same length, but for the purposes of
this exercise we'll say at least two.)

A _scalene_ triangle has all sides of different lengths.

## Note

For a shape to be a triangle at all, all sides have to be of length > 0, and
the sum of the lengths of any two sides must be greater than or equal to the
length of the third side. See [Triangle Inequality](https://en.wikipedia.org/wiki/Triangle_inequality).

## Dig Deeper

The case where the sum of the lengths of two sides _equals_ that of the
third is known as a _degenerate_ triangle - it has zero area and looks like
a single line. Feel free to add your own code/tests to check for degenerate triangles.

* * * *

For installation and learning resources, refer to the
[Ruby resources page](http://exercism.io/languages/ruby/resources).

For running the tests provided, you will need the Minitest gem. Open a
terminal window and run the following command to install minitest:

    gem install minitest

If you would like color output, you can `require 'minitest/pride'` in
the test file, or note the alternative instruction, below, for running
the test file.

Run the tests from the exercise directory using the following command:

    ruby triangle_test.rb

To include color from the command line:

    ruby -r minitest/pride triangle_test.rb


## Source

The Ruby Koans triangle project, parts 1 & 2 [http://rubykoans.com](http://rubykoans.com)

## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.