В правильной усеченной пирамиде в основаниях лежат правильные многоугольники, стороны которых соответственно равны между собой. Боковые грани такой пирамиды - равные между собой равнобокие трапеции. Радиусы окружностей, вписанных в основания, проведенные в точки касания сторон оснований с соответственной окружностью Н и Н1, перпендикулярны к сторонам оснований по свойству радиусов, проведенных в точки касания.
Проведем перпендикуляр из точки касания Н1М верхнего основания на нижнее основание. Тогда отрезок Н1Н перпендикулярен стороне основания АВ по теореме о трех перпендикулярах, то есть является искомой высотой боковой грани.
В прямоугольном треугольнике НН1М угол ∠НН1М = 30° по сумме острых углов. Следовательно, НН1 = 2·НМ по свойству катета, лежащего против угла 30°.
Essay on Sports Hello, folks! Have you ever heard of this well-known saying: “A sound mind in a sound body"? I think the answer in most cases is “yes”. So, we’re discussing the importance of sports today. Not so long ago sports was really important part of our day to day life. But with the rising popularity of television, the Internet and video games, sports and exercises are not so important anymore. There is a reason why we should do sports on daily basis. Going in for sports means to be energetic and healthy. While people who are not keen on it are often seen struggling with illnesses in their adulthood, such as diabetes, obesity etc; Moreover, it helps us not only to improve our body but our mind as well. People who are good at sports also show a lifestyle of excellent quality. They are more active, can make better decisions and find the way out of stressful situations. Not encouraging children to take part in sports activities can make them lazy and peevish as they turn into grown-ups. Also, people who participate in sports competitions are more successful. It is a well-known fact that a man involved in sports activity from the very young age develops a very strong personality. He cultivates what is called the leadership.
6 ед.
Объяснение:
В правильной усеченной пирамиде в основаниях лежат правильные многоугольники, стороны которых соответственно равны между собой. Боковые грани такой пирамиды - равные между собой равнобокие трапеции. Радиусы окружностей, вписанных в основания, проведенные в точки касания сторон оснований с соответственной окружностью Н и Н1, перпендикулярны к сторонам оснований по свойству радиусов, проведенных в точки касания.
Проведем перпендикуляр из точки касания Н1М верхнего основания на нижнее основание. Тогда отрезок Н1Н перпендикулярен стороне основания АВ по теореме о трех перпендикулярах, то есть является искомой высотой боковой грани.
В прямоугольном треугольнике НН1М угол ∠НН1М = 30° по сумме острых углов. Следовательно, НН1 = 2·НМ по свойству катета, лежащего против угла 30°.
НМ = ОН - О1Н1 = 8-5 = 3 ед.
Высота боковой грани НН1 = 6 ед.
Hello, folks! Have you ever heard of this well-known saying: “A sound mind in a sound body"? I think the answer in most cases is “yes”. So, we’re discussing the importance of sports today.
Not so long ago sports was really important part of our day to day life. But with the rising popularity of television, the Internet and video games, sports and exercises are not so important anymore. There is a reason why we should do sports on daily basis. Going in for sports means to be energetic and healthy. While people who are not keen on it are often seen struggling with illnesses in their adulthood, such as diabetes, obesity etc; Moreover, it helps us not only to improve our body but our mind as well.
People who are good at sports also show a lifestyle of excellent quality. They are more active, can make better decisions and find the way out of stressful situations. Not encouraging children to take part in sports activities can make them lazy and peevish as they turn into grown-ups. Also, people who participate in sports competitions are more successful. It is a well-known fact that a man involved in sports activity from the very young age develops a very strong personality. He cultivates what is called the leadership.