Предмет: Геометрия, автор: levkis2010

в равнобедренной трапеции abcd угол b равен 120, основания bc и ad равны 25 и 35 соответственно.Найдите длину боковой стороны трапеции.

Ответы

Автор ответа: RadovoySchwein

1

Ответ: 10.

Объяснение: Так как угол В равен 120 градусов, угол А равен 180-120=60 градусов.

Проведём высоту ВХ. В треугольнике АВХ имеем: угол ВАХ = 60 градусов, угол ВХА прямой, угол АВХ равен 180-(60+90)=30 градусов. Имеем также, что $AX = \frac{35-25}{2} = \frac{10}{2} = 5.$ Так как угол напротив 30 градусов в прямоугольном треугольнике в два раза меньше гипотенузы, то АВ = 5·2=10.

Так как АВ это и есть боковая сторона, то боковая сторона равна 10.

Приложения:

Предыдущий вопрос

Следующий вопрос

Похожие вопросы

Предмет: Геометрия, автор: anonymchek2020

СРОЧНО!!! Знайдіть сторону АС трикутника АВС, якщо кут А=120°; Кут В=45°;ВС=2√6 см

1 год назад

Предмет: История, автор: trofor

1.Підготуйте повідомлення або презентацію на тему "Сучасні релігії світу" дам 60 балов

1 год назад

Предмет: Английский язык, автор: Аноним

Reading

Miss Evans

On a beautiful afternoon in a year now long gone, a big ship set out on its first

voyage from England to America. It was a new ship called the Titanic. For two

days the Titanic went on its way over the sea. Then it entered an ice field and a big

iceberg hit it.

Everyone came out of their rooms. Men were putting the lifeboats over the sides of

the ship down into the water. Then all the men helped the women and children get

into the lifeboats. There wasn’t very much time left. The iceberg was on one side

of the ship. It was like a high white wall.

A woman came to the side of the ship. Her two children were in one of the

lifeboats and she was very much afraid. “My children are on the life boat. I must

go with them,” the woman called to the people in the lifeboat. “There’s no more

room,” someone called out. “If we take one more the lifeboat will sink.” There was

a young woman in the lifeboat called Miss Evans. When she heard the woman

calling, she stood up on the lifeboat and touched one of the men on the arm. “Let

me get back on the ship,” she said. “Let that woman take my place. I have no

children.” “The ship is sinking,” said the man. “You know that?” “Yes,” said Miss

Evans. “I know that.” There was no time to talk. People helped Miss Evans get

back onto the ship. Very soon after that there was a great noise and the Titanic went

down under the water.

1. Read the text. Are the following statements about the text true or false? Change

the false statements to make them true.

1. A big ship set out on its first voyage from America to England.

2. It was an old ship.

3. When the Titanic entered the ice field, a big iceberg hit it.

4. The women helped the men and children get into the lifeboats.

5. The woman wanted to get into one of the boats, because her children were there.

6. She had three children.

7. There was no room in the boat for this woman.

8. Miss Evans let this woman take her place in the boat.

9. Miss Evans had two children.

10. Miss Evans got back to the ship.
11. Soon the Titanic went down under the water.

2. Read the text and choose the correct item to complete the sentence.

1. A big ship set out on its first voyage …

A. from England to Russia

B. from England to America

C. from America to England

2. It was … ship called the Titanic.

A. an old

B. a new

C. a very old

3. The Titanic went on its way over the sea and …

A. was hit by an iceberg

B. was bombed by the airplane

C. was hit by a submarine

4. Women and children got …

A. into the lifeboats

B. to another ship

C. on a desert island

5. The iceberg was like …

A. a big mountain

B. a high rock

C. a high white wall

6. A woman was very much afraid because … in one of the lifeboats.
A. her husband was

B. her two children were

C. her old parents were

7. They could not take the woman into the lifeboat because …

A. it was hit by an iceberg

B. she was afraid of the water

C. there was no room in it

8. Miss Evans was …

A. a young woman

B. an old woman

C. a young teacher

9. Miss Evans had …

A. an old mother on the ship

B. two children

C. no children

10. The woman took place in the … lifeboat.

A. the man’s

B. Miss Evans’

C. her husband’s

1 год назад

Предмет: Литература, автор: vitalinajosipcuk

Запишіть за допомогою прикметників яким на вашу думку має бути справжній друг

6 лет назад

Предмет: Алгебра, автор: raketka1

Розв'язати рівняння (x^2+12x)^2+18(x^2+12x)+81=0

6 лет назад