дан прямоугольный параллелепипед ABCDA1B1C1D1, где AD=a, AB=b, AA1=c. Найдите длину D1P и CN, если P-середина B1C1 N-середина A1B1

дан прямоугольный параллелепипед ABCDA1B1C1D1, где AD=a, AB=b, AA1=c. Найдите длину D1P и CN, если P-середина B1C1 N-середина A1B1
- Предмет:
  Геометрия
- Автор:
  sanaaglass
- 6 лет назад

Ответы 1

Если в данных нет ошибки, то:D1P находится по Пифагору из треугольника D1РC1: √(b²+a²/4) = (√4b²+a²)/2.Из точки N опустим перпендикуляр NK на сторону АВ. В прямоугольном треугольнике СNK KN=AA1=c, CK=D1P=( (√4a²+b²)/2. Тогда СN находится по Пифагору: √(СК²+KN²) =√[(4b²+a²)/4 + c²] = (√4b²+a²+4c²)/2.
- Автор:
  marcowheeler
- 6 лет назад
- 0
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Pete and Nell go to the pictures
One day Pete phoned Nell and. invited her to the pictures. "What film are we going to see?" — she asked. "Oh, it's the one based on the famous Agatha Christie's novel "Witness for the prosecution". "OK, We'll meet near the cinema at 7".
And would you like to join them and see the film? I'm sure you would. So here are some scenes from the script of the film.
Scene I
(The office of Sir Wilfred, one of the finest and most experienced barristers in London. Leonard Vole, a hand¬some young man of about thirty and Mr. Mayherne, his solicitor come to the office. Mr. Mayherne urges Sir Wilfred to take the case of Leonard Vole, who may be arrested any minute on the charge of murdering Mrs. Emily French. Mrs. French, a wealthy widow, was murdered two days ago. She left 80,000 to Leonard Vole, who had visited Mrs. French earlier in the evening on the night of the murder).
MAYHERNE: It's the case of Mrs. Emily French. You've probably seen the reports in the press. When the housekeeper returned from her day off, she found her mistress dead, struck on the back of the head and killed.
SIR WILFRED: I see.
MAYHERNE: I'm sure Vole is harmless chap caught in the web of circumstantial evidence.
VOLE: I haven't murdered anybody, It’ s absurd! But my wife Christine thought I might need a lawyer. That's why I went to see Mr. Mayherne. But now I have two lawyers. It's rather silly, don't you think?
MAYHERNE: Vole, I am a solicitor. Sir Wilfred is a barrister. Only a barrister can plead a case in court. Mr. Vole, isn't it obvious to you that you will be regarded as I he principal suspect in this case? I'm very much afraid you'll be arrested.
Scene II
(Mr. Vole is arrested and now he's in the prisoner's box in one of the courtrooms of the Old Bailey. It is the first day of Vole's trial. The court is in session. The judge is presiding. The jury, consisting of nine men and three women are in the jury box. The counsels for the Prosecution and Defense are in their seats.)
COURT CLERK: Leonard Stephen Vole, you are charged on indictment that you on the 14-th day of October in the County of London murdered Emily Jane French. How say you, Leonard Stephen Vole, are you guilty or not guilty?
VOLE: Not guilty.
JUDGE: Members of the jury, by the oath you have just taken you swore to try this case on the evidence. (To
the prosecutor.) You may proceed for the prosecution, Mr. Myers.
MYERS (rising): The facts in this case are simple. You will hear how the prisoner made the acquaintance of Mrs. Emily French, a woman of 56, how he was treated by her with kindness. Medical testimony will be introduced to prove that death was caused by a blow from a blunt and heavy instrument and it is the case for the Prosecution1
II hat the blow was made by the prisoner Leonard Vole!
VOLE: That's not true! I didn't do it!
MYERS: Among the witnesses you will hear police evidence, also the one of Mrs. French's housekeeper Janet ]Mackenzie, and from the medical and laboratory experts, and the evidence of the murdered woman's solicitor, who drew up her final will.
(The prosecutor proceeds with examination of his witnesses, but cross-examination by Sir Wilfred makes their evidence look rather weak.)
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дан прямоугольный параллелепипед ABCDA1B1C1D1, где AD=a, AB=b, AA1=c. Найдите длину D1P и CN, если P-середина B1C1 N-середина A1B1

Ответы 1

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