{"id":11559,"date":"2022-07-18T14:52:25","date_gmt":"2022-07-18T09:22:25","guid":{"rendered":"https:\/\/mathemerize.com\/?p=11559"},"modified":"2022-07-18T14:52:29","modified_gmt":"2022-07-18T09:22:29","slug":"in-the-figure-two-chords-ab-and-cd-of-a-circle-intersect-each-other-at-the-point-p-when-produced-outside-the-circle-prove-that-i-triangle-pac-triangle-pdb-ii-pa-pb-pc","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/in-the-figure-two-chords-ab-and-cd-of-a-circle-intersect-each-other-at-the-point-p-when-produced-outside-the-circle-prove-that-i-triangle-pac-triangle-pdb-ii-pa-pb-pc\/","title":{"rendered":"In the figure, two chords AB and CD of a circle intersect each other at the point P (when produced) outside the circle. Prove that (i) \\(\\triangle\\) PAC ~ \\(\\triangle\\) PDB (ii) PA.PB = PC.PD"},"content":{"rendered":"
(i)<\/strong>\u00a0 In \\(\\triangle\\)s PAC and PDB, we have :<\/p>\n \\(\\angle\\) APC = \\(\\angle\\) DPB\u00a0 \u00a0 \u00a0 \u00a0 \u00a0(common)<\/p>\n \\(\\angle\\) PAC = \\(\\angle\\) PDB<\/p>\n [\\(\\therefore\\)\u00a0 \\(\\angle\\) BAC = 180 – \\(\\angle\\) PAC\u00a0 and \\(\\angle\\) PDB = \\(\\angle\\) CDB = 180 – (180 – \\(\\angle\\) PAC) = \\(\\angle\\) PAC]<\/p>\n \\(\\therefore\\)\u00a0 By AA similarity, we have :<\/p>\n \\(\\triangle\\) PAC ~ \\(\\triangle\\) PDB<\/strong><\/p>\n (ii)<\/strong>\u00a0 Since \\(\\triangle\\)s PAC ~ PDB, therefore<\/p>\n \\(PA\\over PD\\) = \\(PC\\over PB\\)\u00a0 or\u00a0 PA.PB = PC.PD.<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":" Solution : (i)\u00a0 In \\(\\triangle\\)s PAC and PDB, we have : \\(\\angle\\) APC = \\(\\angle\\) DPB\u00a0 \u00a0 \u00a0 \u00a0 \u00a0(common) \\(\\angle\\) PAC = \\(\\angle\\) PDB [\\(\\therefore\\)\u00a0 \\(\\angle\\) BAC = 180 – \\(\\angle\\) PAC\u00a0 and \\(\\angle\\) PDB = \\(\\angle\\) CDB = 180 – (180 – \\(\\angle\\) PAC) = \\(\\angle\\) PAC] \\(\\therefore\\)\u00a0 By AA similarity, we have …<\/p>\n