Thứ Bảy, 13 tháng 9, 2014

45-Pedal circle of a quadrilateral

1- Let ABCD be a quadrilateral, P be a point on the plane. If \angle APB+\angle CPD=180^0 then have a P' isogonal conjugates of P. (and some result another)


http://www.geogebratube.org/student/m81105

2- If \angle APB+\angle CPD=180^0 and PA.PC=PB.PD then center of Pedal circles is Midpoints of two midpoint of diagonals

3-If \angle APB+\angle CPD=180^0 and PA.PC=PD.PBM is midpoint of ADM meets BC at K. Then \angle MKC = \angle DPC (a generalization Brahmagupta's theorem)

Không có nhận xét nào: