Подошел к концу третий день турнира Колмогорова, и мы, как обычно, радуем вас задачами с него 💥
Задача. На сторонах 𝐵𝐶, 𝐶𝐴 и 𝐴𝐵 треугольника 𝐴𝐵𝐶 выбраны точки 𝐴₁, 𝐵₁ и 𝐶₁ соответственно. Четырёхугольники 𝐴𝐵₁𝐴₁𝐶₁, 𝐵𝐶₁𝐵₁𝐴₁ и 𝐶𝐴₁𝐶₁𝐵₁ описаны около окружностей с центрами 𝐼𝑎, 𝐼𝑏 и 𝐼𝑐 соответственно. Докажите, что площади треугольников 𝐴₁𝐵₁𝐶₁ и 𝐼𝑎𝐼𝑏𝐼𝑐 отличаются в четыре раза.
Подошел к концу третий день турнира Колмогорова, и мы, как обычно, радуем вас задачами с него 💥
Задача. На сторонах 𝐵𝐶, 𝐶𝐴 и 𝐴𝐵 треугольника 𝐴𝐵𝐶 выбраны точки 𝐴₁, 𝐵₁ и 𝐶₁ соответственно. Четырёхугольники 𝐴𝐵₁𝐴₁𝐶₁, 𝐵𝐶₁𝐵₁𝐴₁ и 𝐶𝐴₁𝐶₁𝐵₁ описаны около окружностей с центрами 𝐼𝑎, 𝐼𝑏 и 𝐼𝑐 соответственно. Докажите, что площади треугольников 𝐴₁𝐵₁𝐶₁ и 𝐼𝑎𝐼𝑏𝐼𝑐 отличаются в четыре раза.
You may recall that, back when Facebook started changing WhatsApp’s terms of service, a number of news outlets reported on, and even recommended, switching to Telegram. Pavel Durov even said that users should delete WhatsApp “unless you are cool with all of your photos and messages becoming public one day.” But Telegram can’t be described as a more-secure version of WhatsApp. Oleksandra Matviichuk, a Kyiv-based lawyer and head of the Center for Civil Liberties, called Durov’s position "very weak," and urged concrete improvements. During the operations, Sebi officials seized various records and documents, including 34 mobile phones, six laptops, four desktops, four tablets, two hard drive disks and one pen drive from the custody of these persons. Ukrainian forces have since put up a strong resistance to the Russian troops amid the war that has left hundreds of Ukrainian civilians, including children, dead, according to the United Nations. Ukrainian and international officials have accused Russia of targeting civilian populations with shelling and bombardments. "Your messages about the movement of the enemy through the official chatbot … bring new trophies every day," the government agency tweeted.
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