MathDB

6

Part of 2001 Baltic Way

Problems(1)

5 concyclic points A,B,C,D,E have AB||EC, AC||ED

Source: Baltic Way 2001

11/17/2010
The points A,B,C,D,EA, B, C, D, E lie on the circle cc in this order and satisfy AB∥ECAB\parallel EC and AC∥EDAC\parallel ED. The line tangent to the circle cc at EE meets the line ABAB at PP. The lines BDBD and ECEC meet at QQ. Prove that ∣AC∣=∣PQ∣|AC|=|PQ|.
geometryparallelogramgeometry proposed