Gratuite, doar pentru 2D:
DraftSight (de departe cel mai puternic program de desen gratuit, si foarte asemanator cu AutoCAD)
Medusa4 (un program foarte puternic, putin mai greu de invatat decat DraftSight sau AutoCAD) - lucrez cu el la munca, ocazional, cand am nevoie doar de 2D
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Cu plata:
Autodesk AutoCAD LT (pentru 2D)
Autodesk AutoCAD (2D si 3D)
DSS SolidWorks (3D)
Siemens Solid Edge (3D)
Autodesk Inventor (3D)
in ultimele 3, cerul e limita, iar SolidWorks e foarte intuitiv.
Sau
Geometry Expressions (poti folosi varianta gratuita, GX Web)
https://www.youtube.com/watch?v=p9w790OcJyI
https://www.geometryexpressions.com/
GeoGebra (modulul Geometry) (e gratuit, si mult mai complex decat GXWeb)
https://www.youtube.com/watch?v=atpYhkucxjs
https://www.geogebra.org/download
SODEV Mehanical Calculator (Modulul Math)
https://goo.gl/images/ZTetVt
https://goo.gl/images/nm5DpK