Let ABCD be a tangential quadrilateral and O be the center of the inscribed circle (see the figure below). if M and N are the midpoints of the diagonals AC and BD, prove that M, O, and N are collinear points.
Newton line is the line that connects the midpoints of the two diagonals in a quadrilateral other than a parallelogram.
Tangential quadrilateral or circumscribed quadrilateral is a convex quadrilateral whose sides are all tangent to a circle inside it.
This step-by-step interactive illustration was created with GeoGebra.
GeoGebra is free and multi-platform dynamic mathematics software for all levels of education that joins geometry, algebra, tables, graphing, statistics and calculus application, intended for teachers and students. Many parts of GeoGebra have been ported to HTML5.
Ten problems: 1411-1420
Tangential or Circumscribed Quadrilateral
Incenter, Inscribed circle
Circle Tangent Line
HTML5 and Dynamic Geometry
View or Post a solution