Задача. Дан выпуклый четырехугольник 𝐴𝐵𝐶𝐷. Известно, что окружности, вписанные в треугольники 𝐴𝐵𝐶 и 𝐴𝐷𝐶 касаются друг друга. Докажите, что окружности, вписанные в треугольники 𝐴𝐵𝐷 и 𝐶𝐷𝐵 также касаются друг друга.
Пусть первые снежные сугробы добавят вам новогоднего настроения ☃️
Задача. Дан выпуклый четырехугольник 𝐴𝐵𝐶𝐷. Известно, что окружности, вписанные в треугольники 𝐴𝐵𝐶 и 𝐴𝐷𝐶 касаются друг друга. Докажите, что окружности, вписанные в треугольники 𝐴𝐵𝐷 и 𝐶𝐷𝐵 также касаются друг друга.
Пусть первые снежные сугробы добавят вам новогоднего настроения ☃️
Telegram was co-founded by Pavel and Nikolai Durov, the brothers who had previously created VKontakte. VK is Russia’s equivalent of Facebook, a social network used for public and private messaging, audio and video sharing as well as online gaming. In January, SimpleWeb reported that VK was Russia’s fourth most-visited website, after Yandex, YouTube and Google’s Russian-language homepage. In 2016, Forbes’ Michael Solomon described Pavel Durov (pictured, below) as the “Mark Zuckerberg of Russia.” In addition, Telegram's architecture limits the ability to slow the spread of false information: the lack of a central public feed, and the fact that comments are easily disabled in channels, reduce the space for public pushback. Lastly, the web previews of t.me links have been given a new look, adding chat backgrounds and design elements from the fully-features Telegram Web client. The last couple days have exemplified that uncertainty. On Thursday, news emerged that talks in Turkey between the Russia and Ukraine yielded no positive result. But on Friday, Reuters reported that Russian President Vladimir Putin said there had been some “positive shifts” in talks between the two sides. In 2014, Pavel Durov fled the country after allies of the Kremlin took control of the social networking site most know just as VK. Russia's intelligence agency had asked Durov to turn over the data of anti-Kremlin protesters. Durov refused to do so.
from ca