The solution of mathematical tasks in the ancient Greek
Trisection of angles
angle=0 - no solution
180>angle>0 - general solution (consists of 4 parts)

the first part
Trisection of angles-similarly-c1.png
1.initial conditions of angle CAB
2.caliper A- ( free) , gets the points D and E
3.straightedge ( ruler ) DE
4.caliper E-ED
Trisection of angles-similarly-c2.png
5.caliper D-DE , gets the points F and G
6.straightedge ( ruler ) FG , gets the point H
7.caliper H-HD