Стороны прямоугольника равны a и k. Найдите радиус окружности, описанной около этого прямоугольника
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В треугольнике АВС угол А=90, а угол С на 40 больше угла В. Найдите углы В и С.

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I went home. My parents were very kind and tried to make me feel better, saying it didn't matter, but that wasn't the point. They didn't understand that I couldn't even sit at the piano, my beautiful piano. I was scared, I didn't want to fail again. Then my mother had an idea. She convinced me to go and see another teacher, Mrs Finlay. I didn't want to but in the end I went to see her. She was kind and gentle, and she understood that I was afraid to play the piano, that it was almost like starting again.

Mrs Finlay was very patient. I went to see her every week and little by little I began to enjoy playing again. I began to practise again every day on my beautiful piano. I was so happy. I had gained back my pride and self-confidence.

It has been a very difficult time in my life, but I don't regret it. I feel stronger because of it. I lost some things for a time - my pride and self-confidence, but I got them back again with all my hard work and help from other people. I'm ready now, I've got another chance to play in the next national piano competition and make my dream come true. When I do, I want my parents and Mrs Woodham and Mrs Finlay to be there.

К окружности с центром O проведены две касательные, которые пересекаются в точке K, B и С - точки касания. KO = 20,5; KB = 20. Найдите радиус окружности.

известно что а и b положительные числа и a>b.сравните 1/a и 1/b как его решать??объясните и напишите ответ