Geometry Problem

Level: Mathematics Education, High School, Honors Geometry, College.

Click the figure below to see the complete problem 628.

## Thursday, June 23, 2011

### Problem 628: Cyclic Quadrilateral, Congruence, Parallel Lines

Labels:
congruence,
cyclic quadrilateral,
parallel

Subscribe to:
Post Comments (Atom)

Isosceles Triangles ABE and DCF are equiangular

ReplyDelete(vertical angles at B and C being equal).

So

<AEB = <DFC,

and on taking supplements

<AED = <AFD

and thus

A,E,F,D are concyclic

Now <AFE = <ADB = <ACB

Hence EF // BC