Предмет: Геометрия, автор: 007123

в окружность вписан правильный треугольник и около окружности описан правильный треугольник.найдите отношение площадей этих треугольников.

 

Пусть а(3) -сторона вписанного треугольника,R-радиус этой окружности,b (3) -cторона описанного треугольника,S-площадь вписанного треугольника,Q-площадь описанного треугольника,тогда a(3)=R*________,а S=a(3)квадрат*_____=________*Rквадрат;0,5b(3)=R:tg________,откуда в(3)=_________R.

Поэтому Q=b(3) квадрат*_________=____________=__________Rквадрат.

Отсюда S:Q=______________:______________=_______________

 

(Пожалуйста заполните прочерки в решении,СПАСИБО)

Ответы

Автор ответа: Аноним
0

 найдите отношение площадей этих треугольников.

a(3)=R*√3

S=a(3)квадрат*√3/4=3√3/4*Rквадрат;

0,5b(3)=R:tg30

в(3)=2*√3R.

Q=b(3) квадрат*1/4=(2*√3R)^2*1/4=3*Rквадрат.

S:Q=3√3/4*R^2:3*R^2=√3/4:1=√3/4

Похожие вопросы
Предмет: Английский язык, автор: zOngate
Раскройте скобки, используя подходящую форму инфинитива (с частицей to, без частицы to или с окончанием –ing)
1. I (like) dance.

2. I'd (like) dance.

3. He hates (get up) early.

4. I shall do all I can (help) you.

5. She made me (repeat) my words several times.

6. Try (take) an aspirin for your headache.

7. I saw him (enter) the room.

8. She did not let her mother (go) away.

9. We enjoy (sit) in the garden.

10. Do you like (listen) to good music?

11. Would you like (listen) to good music?

12. That funny scene made me (laugh).

13. I like (play) the guitar.

14. I remember (post) the letter yesterday.

15. My brother can (speak) French.

16. We had (put) on our overcoats because it was cold.

17. They wanted (cross) the river.

18. It is high time for you (go) to bed.

19. May I (use) your telephone?

20. He stopped (smoke) three month ago.

21. They heard the girl (cry) out with joy.

22. I would rather (stay) at home today.

23. He did not want (play) in the yard any more.

24. Would you like (go) to England?

25. This job means (work) long hours and not (earn) very much.

26. You look tired. You had better (go) home.

27. I wanted (speak) to Nick, but could not find his telephone number.

28. It is time (get) up.

29. Let me (help) you with your homework.

30, I was planning (do) a lot of things yesterday. I'd like (speak) to you.

31. I think I shall be able (solve) this problem.

32. What makes you (think) you are right?

33. He must (do) it.

34. Pete can't (concentrate) with the radio on.

35. We don't feel the earth (move).
Предмет: Алгебра, автор: pvpnara