Tracing angles
Linear paths

Data :

• an angle $\widehat{BAC}=\alpha$ ;

• a straight line (OD).

Layout :

• Determine the angle (by drawing an arc of a circle of any radius R ₁ and center A which intersects [AB] at M and [AC] at N ;

• from point M, trace the arc of a circle R ₂ passing through N ;

• From point O,...