Задача. В равнобедренном треугольнике 𝐴𝐵𝐶 (𝐴𝐵 = 𝐴𝐶 < 𝐵𝐶) на сторонах 𝐵𝐶 и 𝐴𝐵 отмечены точки 𝑃 и 𝑄 соответственно так, что 𝑃𝑄 перпендикулярно 𝐴𝐵 и 𝑃𝑄 делит периметр треугольника пополам. Докажите, что 𝐴𝐵 = 𝐵𝑃.
Задача. В равнобедренном треугольнике 𝐴𝐵𝐶 (𝐴𝐵 = 𝐴𝐶 < 𝐵𝐶) на сторонах 𝐵𝐶 и 𝐴𝐵 отмечены точки 𝑃 и 𝑄 соответственно так, что 𝑃𝑄 перпендикулярно 𝐴𝐵 и 𝑃𝑄 делит периметр треугольника пополам. Докажите, что 𝐴𝐵 = 𝐵𝑃.
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. The message was not authentic, with the real Zelenskiy soon denying the claim on his official Telegram channel, but the incident highlighted a major problem: disinformation quickly spreads unchecked on the encrypted app. Individual messages can be fully encrypted. But the user has to turn on that function. It's not automatic, as it is on Signal and WhatsApp. Channels are not fully encrypted, end-to-end. All communications on a Telegram channel can be seen by anyone on the channel and are also visible to Telegram. Telegram may be asked by a government to hand over the communications from a channel. Telegram has a history of standing up to Russian government requests for data, but how comfortable you are relying on that history to predict future behavior is up to you. Because Telegram has this data, it may also be stolen by hackers or leaked by an internal employee. What distinguishes the app from competitors is its use of what's known as channels: Public or private feeds of photos and videos that can be set up by one person or an organization. The channels have become popular with on-the-ground journalists, aid workers and Ukrainian President Volodymyr Zelenskyy, who broadcasts on a Telegram channel. The channels can be followed by an unlimited number of people. Unlike Facebook, Twitter and other popular social networks, there is no advertising on Telegram and the flow of information is not driven by an algorithm.
from es
