> Divide into two equal angles

a. circle an arc circle with point A as center with an arbitrary radius R is cut off feet angle AB and AC dititik-point P and O.
 
b. Create with P and O as the center of the circle arc with arbitrary radii R2 and R3 (R2 = R3) the same large.
The two arcs intersect the circle at T
 
c. Pull the line AT BAT angle = angle TAC.