tag:blogger.com,1999:blog-6933544261975483399.post385290265898073077..comments2024-04-22T04:55:16.794-07:00Comments on Go Geometry (Problem Solutions): Geometry Problem 1242: Quadrilateral, Four Interior and Exterior Angle Bisectors, Collinearity, Concurrent LinesAntonio Gutierrezhttp://www.blogger.com/profile/04521650748152459860noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-6933544261975483399.post-81331025978482054332016-08-02T18:20:27.653-07:002016-08-02T18:20:27.653-07:00Let BC and AD extended meet at P
Then C2 is the e...Let BC and AD extended meet at P<br /><br />Then C2 is the excentre of Tr. PCD<br />C1 is the in Centre of Tr. PCD<br />A2 is the in Centre of Tr. PAB<br />A1 is the excentre of Tr. PAB<br /><br />It follows that PC1C2A2A1 are collinear points, being on the internal bisector of < P. The concurrency of BC,AD and this line is also self evident<br /><br />Similarly for AB and DC extended which when extended say meets at Q. Then Q and B1,B2,D1,D2 are collinear and the concurrency of this line and AB and DC is evident<br /><br />Sumith Peiris<br />Moratuwa<br />Sri LankaSumith Peirishttps://www.blogger.com/profile/06211995240466447227noreply@blogger.com