Рассмотрим треугольники АВС и MNC. Они подобны по второму признаку подобия: две стороны одного треугольника пропорциональны двум сторонам другого треугольника и углы, заключенные между этими сторонами, равны: - CN : CB = CM : CA = 9 : 12 = 12 : 16 = 3 : 4 (коэф. подобия 3/4); - угол С - общий для треугольников. У подобных треугольников соответственные углы ВАС и NMC равны. Они являются также соответственными углами при пересечении двух прямых АВ и MN секущей АС. Используем один из признаков параллельности двух прямых: если при пересечении двух прямых секущей соответственные углы равны, то прямые параллельны. Значит, AB II MN.
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.
20-14=6 основа