@options; @figure; A = point( -2.5 , 0 ); B = point( 0.5 , 0 ); sAB = segment( A , B ); cediaAB = cercledia( A , B ); d1 = perpendiculaire( A , sAB ); d2 = perpendiculaire( B , sAB ); C = point( 0.5 , -4 ); d3 = perpendiculaire( C , d1 ); @analyse;