Circle
2013-03-16 11:44 pm
ABCD is a cyclic quadrilateral (A,B,C and D in clockwise order). The 2 diagonals AC and BD intersects at right angle to each other at point P. X is a point on CD and Y is a point on AB such that XPY is a straight line and perpendicular to AB. Prove that DX = XC.
回答 (2)
2013-03-17 8:18 pm
✔ 最佳答案
∠XDP = ∠PAB (angles in same segment)= ∠YPB (∠AYP, ∠APB are right angles)
= ∠DPX (vert opp)
therefore, DX = XP
Similarly,
∠XCP = ∠PBA (angles in same segment)
= ∠YPA (∠AYP, ∠APB are right angles)
= ∠CPX (vert opp)
therefore, XC = XP
So, DX = XC
2013-03-17 7:07 am
How about the Y?
收錄日期: 2021-04-13 19:21:55
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https://hk.answers.yahoo.com/question/index?qid=20130316000051KK00184