https://www.amcallinone.com/types-of-lines-in-engineering-drawing-%e0%a4%87%e0%a4%82%e0%a4%9c%e0%a5%80%e0%a4%a8%e0%a4%bf%e0%a4%af%e0%a4%b0%e0%a4%bf%e0%a4%82%e0%a4%97-%e0%a4%a1%e0%a5%8d%e0%a4%b0%e0%a4%be%e0%a4%87%e0%a4%82/