3 -bob planimetriya 1 Burchaklar. Masofalar

A) 140⁰ B) 120⁰ C) 110⁰ D) 80⁰ E) 60⁰

27. (00-5-52) Uchburchak o'tkir burchakli bo'lishi uchununing α; βva γ burchaklari orasida qanday muno-

sabatlar o'rinli bo'lishi kerak?

A) B) C) D) E)

28. (01-2-39) Uchburchakning burchaklari arifmetik progressiyani tashkil etadi. Agar uchburchakning eng kichik burchagi 20⁰ bo'lsa, eng katta burchagini toping.

A) 90⁰ B) 95⁰ C) 100⁰ D) 105⁰ E) 110⁰

29. (01-6-52) Teng yonli uchburchakning asosidagi tashqi burchagi, unga qo'shni burchakdan 40⁰ ga

katta. Teng yonli uchburchakning uchidagi burchagini toping.

A) 30⁰ B) 40⁰ C) 42⁰ D) 36⁰ E) 38⁰

30. (01-7-54) Teng yonli uchburchakning ichki burchaklari va uchidagi tashqi burchagi yig'indisi 21/16¼

ga teng. Uchburchakning teng burchaklari yig'indisini toping.

A) B) C) D) E)

31. (01-8-36) Uchburchakning tashqi burchaklaridan biri 120⁰ shu burchakka qo'shni bo'lmagan ichki

burchaklarining ayirmasi 300 ga teng. Uchburchakning ichki burchaklaridan kattasini toping.

A) 75⁰ B) 70⁰ C) 90⁰ D) 85⁰ E) 80⁰

32. (01-8-38) ABC uchburchakning B va C burchaklari bissektrisalari 128⁰ burchak ostida kesishadi.

A burchakning qiymatini toping.

A) 104⁰ B) 76⁰ C) 72⁰ D) 66⁰ E) 52⁰

33. (02-4-45) Teng yonli uchburchakning asosidagi burchak uning uchidagi burchakning 75% iga teng.

Uchburchakning uchidagi burchagini toping.

A) 90⁰ B) 120⁰ C) 135⁰ D) 72⁰ E) To'g'ri javob keltirilmagan

34. (02-5-48) Teng yonli uchburchakning uchidagi burchagi 40⁰ ga teng. Asosidagi burchakning bis-

sektrisasi va shu burchakka qarama-qarshi tomon orasidagi burchakni toping.

A) 60⁰ B) 75⁰ C) 85⁰ D) 65⁰ E) 50⁰

35. (02-8-23) ABC uchburchakda A va B burchaklari bissektrisalari kesishishidan hosil bo'lgan kichik

burchak 40⁰ ga teng. Uchburchakning C burchagini toping.

A) 100⁰ B) 90⁰ C) 80⁰ D) 120⁰ E) 70⁰

36. (02-9-48) AN ABC uchburchakning bissektrisasi. Agar AB = AN va C = 300 bo'lsa, B burchak

necha gradusga teng?

A) 40⁰ B) 50⁰ C) 60⁰ D) 70⁰ E) 80⁰

37. (03-2-45) Uchburchakning ikkita burchagi yig'indisi 70⁰ ga teng. Shu burchaklarning bissektrisalari

kesishishidan hosil bo'lgan burchaklardan kichigi necha gradusga teng.

A) 50⁰ B) 45⁰ C) 40⁰ D) 35⁰ E) 25⁰

38. (03-3-56) Teng yonli uchburchakning asosidagi burchagi 30⁰ ga teng. Shu uchburchakning yon tomon-

laridan biri va ikkinchi yon tomonga tushirilgan balandligi orasidagi burchakni toping.

A) 50⁰ B) 120⁰ C) 60⁰ D) 45⁰ E) 30⁰

39. (03-6-72) Teng yonli uchburchakning uchidagi tashqi burchagi o'sha uchidagi ichki burchagidan 4 mar-

ta katta. Uchburchakning asosidagi tashqi burchagi necha gradus?

A) 108⁰ B) 110⁰ C) 98⁰ D) 102⁰ E) 112⁰

3.3.3 To'g'ri burchakli uchburchak.

Pifagor teoremasi.

c-gipotenuza, a,b-katetlar bo'lsin.

1. c² = a² + b² ga teng.

2. Gipotenuzaga tushirilgan mediana uning yarmiga teng. m_c =

1. (96-10-43) To'g'ri burchakli uchburchak katetlaridan biri 12 sm, gipotenuza esa ikkinchi katetdan 6 sm uzun. Gipotenuzaning uzunligini toping.

A) 15 B) 25 C) 26 D) 18 E) 32

2. (96-1-40) To'g'ri burchakli uchburchakning gipotenuzasi 25 sm, katetlari esa o'zaro 3 : 4 nisbatda.

Shu uchburchakning kichik katetini toping.

A) 10 B) 12 C) 9 D) 15 E) 20

3. (96-9-91) To'g'ri burchakli uchburchak katetlaridan biri 12 sm, ikkinchisi esa gipotenuzadan 8 sm qisqa. Shu uchburchak gipotenuzasini toping.

A) 15 B) 16 C) 25 D) 13 E) 29

4. (97-1-33) Uchburchak burchaklarining kattaliklari nisbati 1 : 1 : 2 kabi, katta tomonining uzunligi esa 13 ga teng. Uchburchakning katta tomoniga tushirilgan balandligini toping.

A) 6; 5 B) 12 C) 8 D) 5 E) 10

5. (97-4-45) To'g'ri burchakli uchburchak gipotenuzasining shu gipotenuzaga tushirilgan medianaga nisbatini toping.

A)3 B) 4 C) 2, 5 D) 2 E) 1, 5

6. (00-1-55) Agar m > n > 0 bo'lib, a = m² + n²; b = m²- n² va c = 2mn uchburchak tomonlarining uzunliklari bo'lsa, quyidagi tasdiqlardan qaysi biri to'g'ri?

A) uchburchak o'tkir burchakli B) uchburchak o'tmas burchakli C) uchburchak to'g'ri burchakli D)asosidagi burchaklari 45⁰ ga teng bo'lmagan teng yonli uchburchak E)muntazam uchburchak

7. (97-11-33) Burchaklarining kattaliklari nisbati 9 :5 : 4 kabi bo'lgan uchburchakning katta tomoniga tushirilgan medianasi 12; 5 ga teng. Uchburchakning katta tomonini toping.

A)20 B) 16 C) 25 D) 32 E) 26

8. (00-7-42) ABC uchburchakning C uchidagi tashqi burchagi 90⁰ ga teng. Agar CA = 12 va CB = 5 bo'lsa, AB tomonga tushirilgan CD mediananing uzunligini toping.

A)6 B) 6, 5 C) 5 D) 5, 5 E) 7

9. (96-6-30) Tomonlari 10; 8 va 6 bo'lgan uchburchakning katta tomoniga o'tkazilgan medianasini toping.

A)7 B) 6 C) 3 D) 4 E) 5

10. (02-4-49) Uchburchakning burchaklari 1 : 2 : 3 kabi nisbatda. Uchburchak katta tomonining kichik

tomoniga nisbatini toping.

A)1 B) 2 C) 3 D) 4 E) 5

11. (02-8-31) ABC to'g'ri burchakli uchburchakda AB gipotenuza. AM va BN bissektrisalar. Agar AB =12 va

AM² + BN² = 169 bo'lsa, MN ning uzunligini toping.

A)5 B) 2,5 C) D) 6 E) 4

12. (03-11-33) To'g'ri burchakli uchburchakda o'tkir burchaklarining medianalari uzunliklari 15 va 6

ga teng. Gipotenuza uzunligini toping.

A)18 B) 16 C) 20 D) 21 E) 19
Katetlarning gipotenuzadagi proyeksiyalari.

a² = xc (x kesma -a katetning c dagi proyeksiyasi).

b² = yc (y kesma -b katetning c dagi proyeksiyasi).

Shuning uchun

h² = xy:

(97-6-32) To'g'ri burchakli uchburchakning kateti 7 ga,

uning gipotenuzaga proyeksiyasi 1; 96 ga teng. Ikkinchi

katetning uzunligini toping.

12 B) 16 C) 24 D) 15 E) 26

Yechish: a katetning c gipotenuzadagi proyeksiyasi x ga teng bo'lsa. c∙x = a² formula o'rinli. Shuning uchun

c ∙1,96 = 7², ya'ni c == 25 . U holda ikkinchikatet b == 24 ga teng. J: 24 (C).

1. (96-7-45) To'g'ri burchakli uchburchakning katet-lari 5 : 6 kabi nisbatda, gipotenuzasi esa 122 ga teng. Gipotenuzaning balandlik ajratgan kesmalarini toping.

A) 45 va 77 B) 42 va 80 C) 50 va 72 D) 32 va 90 E) 60 va 62

2. (96-9-34) To'g'ri burchakli uchburchakning bir kateti 10 sm ga, gipotenuzaga tushirilgan balandligi 6sm ga teng. Uning ikkinchi katetini toping.

A) 9 B) 7 C) 6, 5 D) 7, 5 E) 8

3. (96-12-94) To'g'ri burchakli uchburchakning bir kateti 5 ga, gipotenuzaga tushirilgan balandligi 3 ga teng. Uning ikkinchi katetini toping.

A) 3, 5 B) 3, 75 C) 4 D) 3, 8 E) 3,9

4. (97-1-32) To'g'ri burchakli uchburchakning katetlari 15 va 20 ga teng. Katta katetning gipotenuzadagi proyeksiyasini toping.

A) 12 B) 14,5 C) 16 D) 16,5 E) 18

5. (97-2-26) To'g'ri burchakli uchburchakning gipotenuzasi 10 ga teng, bir kateti 6 ga teng. Bu katet-

ning gipotenuzadagi proyeksiyasini toping.

A) 4 B) 3,6 C) 4, 2 D) 3,4 E) 3,8

6. (97-3-45) Katetlarining nisbati 3 : 2 kabi bo'lgan to'g'ri burchakli uchburchakning balandligi gipotenuzasini uzunliklaridan biri ikkinchisidan 6 ga ko'p bo'lgan ikki qismga ajratadi. Berilgan uchburchakning

gipotenuzasini toping.

A) 5,2 B) 4,8 C) 6 D) 8 E) 7,6

7. (97-7-45) Gipotenuzasi 50 ga teng bo'lgan to'g'ri burchakli uchburchakning katetlari nisbati 4 : 3 ga teng. Gipotenuzaga tushirilgan balandlik uni qanday kesmalarga ajratadi?