Better-half

Better-half is an England English word. The concept of the perpendicular bisector is due to this. The perpendicular bisector can help divide a line into any number of parts, with set-squares which can be manufactured. Possibly parallel lines can be drawn by masters as the online software GeoGebra is able to. I got it. One tangent to two semi-circles which sit on the same floor.
Perpendicular bisector is one of the top concepts of the world.
I was able to trisect an angle. GeoGebra has a tool for polygons. Hence it is possible to trisect an angle too.