Write a program that will determine the type of a triangle. It should take the lengths of the triangle's three sides as input, and return whether the triangle is equilateral, isosceles or scalene.
We are looking for simple but good solutions that properly solve the problem. Pay special attention to tests, readability of code and error cases.
Besides solving the explicit problem above, the project should demonstrate decision-making skills while demonstrating Fullstack Engineering knowledge and abilities.
- Conceptual understanding
My geometry was a bit rusty, so the first step was to visit Google. After refreshing some basic concepts from Euclidean geometry, I had a conceptual understanding of the problem and a possible solution.
given a,b,c
check if a,b,c forms a valid triangle,
then determine triangle type
- Technology stack
A lot of engineering lies in choosing the right tools for the job. I decided to use tools that emphasize speed and flexibility (Python or JavaScript). Since the problem didn't require high numerical precision and I also wanted to demonstrate some Frontend abilities, I choose JavaScript. This isomorphic stack would allow me to easily extend a Node.js app with a web interface, using React.
- Workflow
I choose to frame the assignment, more as a real-world problem – a moving target, with changing priorities and multiple solutions. From my experience, the best process is iterative with frequent deliveries. With this agile approach, here are the first milestones:
-
simple command-line app taking 3 inputs (length of sides: a,b,c) and returning whether the triangle is an equilateral, isosceles or scalene
-
simple web-interface with 3 inputs controls and text display for return triangle type
-
make web-interface more interactive with a visual display of triangle
-
move visualizations to canvas, to easily extend shapes
-
add TypeScript / Flow and do more rigoures testing of React components
- Make sure you've a recent version of Node and NPM installed on your computer
- cd into the project directory and
npm installto download required modules
After installation, start the dev server by running npm start. You can now access the web-interface from http://localhost:3000/ in your browser
After installation, run the tests by running npm test. This will use the local jest installation to run the test environment.
- I've only tested the web-interface in newer versions of Chrome