:help: A group including myself are working on a project and it'll use some AutoCAD like functionality like drawing a rectangle, circles, lines, polylines, etc.

As I search through the web, the only guides I was able to find was literally like a drawing/sketch application. Is there some guides you could offer that will help me achieve the output I'm searching for?

A better example would be the AndCAD application in Playstore. No 3Ds. Just plain 2D Drawings. Hoping you could help us guys.