This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Orthosystem SVG.svg Orthosystem by user User Magister Mathematicae thumb own Limaner other versions Eukleides code box triangle orthocenter draw dot mark intersection line line right point line mark intersection line line right point line mark intersection line line right draw dot draw dot draw dot thickness draw draw