Discussion Forum

November 2018 Online ZIML Discussion and Announcements

November 2018 Online ZIML Discussion and Announcements

Please use this thread for any questions or feedback from the November 2018 Online ZIML Competition.

We hope everyone had fun competing!

Re: November 2018 Online ZIML Discussion and Announcements

Announcement Regarding Division M Question 7:

Question 7 on the DIvision M Monthly Contest involved a diagram (not drawn to scale) in the shape of a star that included a pentagon in the middle:

The problem stated that $\angle CAD = 20^\circ$ AND that all the outside triangles $\triangle AFJ$, $\triangle BGF$, etc, were all isosceles.

This, however, is impossible, as it both implies that pentagon $FGHIJ$ has interior angles of $100^\circ$ and that it is equiangular (so would have angles of $108^\circ$).

For scoring of the competition, the problem has been removed. The updated problem will state that only $\triangle AFJ$, $\triangle BGF$, and $\triangle CHG$ are isosceles (with $\angle CAD$ still $20^\circ$).