Complex 2d figure - dynamic intelligent fact-checking

An often overlooked gem of Geometry Calculator PRO, only one click away from the app's start screen, is the page appropriately called "Complex 2d figure (BETA)".

By using an intuitive flow that consists of adding fixed or floating points, line segments between any two points, and angles between adjacent segments, you can easily draw triangles, quadrilaterals, parallel or perpendicular lines, etc. An intelligent algorithm helps you along the way. It is almost impossible to make a mistake and get the wrong result! The algorithm will draw your input, plus any resulting intersection points, on a neat square canvas at the top of the page, and it will also compute sizes and apply geometry rules on the fly. At the bottom of the page you will see a list of numerical and symbolic facts that will surely help you understand the problem you are trying to solve. And because the list can get pretty long, I've added four (at the time of this writing) checkboxes to help you filter out uninteresting facts.

In the future I may also add more detailed explanations of what is going on under the hood. For example, the algorithm often applies a classic theorem called "triangle inequality" (the sum of any two sides of a triangle must be greater than the remaining side) when checking or enforcing symbolic or numerical equality betweeen segment sizes.

As with my previous posts on this blog, here is a link to a short YouTube video wherein you can watch the algorithm in action:

Watch video!

I'm always open to questions, suggestions and constructive criticism!

Andrei