Categories
Intermediate

Eclipsing earth

Two circles with their centres. The quadrilateral ABCD is cyclic and has two sides tangent to the small circle. Prove that BD is also tangent.

Scroll down for a solution to this problem.

Solution

Solution by Stéphane Bernard.

AE and DE are bisectors in triangle ABD => E is the incircle center => BD tangent.

Video

Please find here the video solution: Video: Eclipsing earth.

🤞 Don’t miss these puzzles!

Subscribe to the weekly geometry puzzle e-mail.

Leave a Reply

Your email address will not be published. Required fields are marked *

Optionally add an image (JPEG only)