Вопрос школьника по предмету Геометрия
Периметр равнобедренного треугольника ABC равен 44 см. Из вершины C его основания AC проведена медиана CM. Найдите стороны данного треугольника, если периметр треугольника BCM на 8 см меньше периметра треугольника ACM.
Ответ учителя по предмету Геометрия
Обозначаем:
AB = BC = a
AC = b
CM = d
Тогда периметр треугольника BCM равен a + d + a/2
Периметр треугольника АСМ равен b + d + a/2
По условию (b + d + a/2) — (a + d + a/2) = 8, то есть b — a = 8
А периметр треугольника АВС равен 2a + b = 44
Решаем систему, получаем:
АВ = ВС = 12
АС = 20
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In 1608 an Englishman whose name was Thomas Coryate visited Italy. He liked the country and noted down every interesting thing he found. But there was one thing which he found more interesting than the others. In his diary Thomas wrote, “When the Italians eat meat, they use small forks. They don’t eat with hands because, as they say , do not always have clean hands”.
Before leaving for England, Thomas Coryate bought a few forks.
At home Thomas gave a dinner party to show the invention to his friends. When the servant brought the steak, he took out a fork and began to eat like they did in Italy.
Everybody looked at him in surprise. When he told his friends what it was, they all wanted to take a good look at the strange thing. All his friends said that the Italians were very strange people because the fork was very inconvenient.
Thomas Coryate tried to prove the opposite. He said it was not nice to eat with one’s fingers because they were not always clean.
Everybody got angry at that . Did Mr. Coryate think that people inEngland always had dirty hands? And weren’t the ten fingers they had enough for them?
Thomas Coryate wanted to show that it was very easy to use the fork. But the first piece of meat he took with the fork fell to the floor. His friends began to laugh and he had to take the fork away.
Only fifty years later people in England began to use forks.
1. Translate the following sentences into Russian:
In 1608 an Englishman whose name was Thomas Coryate visited Italy.
But there was one thing which he found more interesting than the others.
He said it was not nice to eat with one’s fingers because they were not always clean.
But the first piece of meat he took with the fork fell to the floor.
2. Answer the questions:
Why did the Italians eat with the forks?
What did he give at home to show the invention of the Italians?
Why did his friends begin to laugh?
When did people in England begin to use forks?
3. Correct according to the contents of the text :
They eat with the hands because, as they say, do not always have clean hands.
Everybody got happy at that.
Only seventy years later people in England began to use forks.
When the servant brought the steak, he took out a knife and began to eat like they did in Italy.
1. (Жили,Существовали) старик со старухой у самого синего моря. 2. Вот (Пошел,Отправился) он к синему морю. 3. Приплыла к нему рыбка, (спросила,задала вопрос). 4. Ещё пуще старуха (ругается,бранится).