1 8-sinf geom yangi. 1-8-bet. 2015(boshi). p65

§ ga doir qo‘shimcha mashqlar

389. 
     ABC uchburchakda A burchak o‘tmas, BP — uchburchakning balandligi. BC² = AB² + AC² + 2AP • AC ekanini isbotlang.
     
390. 
     Tomonlari: 1) ²⁵, ²⁵, 6; 2) 13, 3713, 47ga teng bo‘lgan uchbur­chakning eng katta balandligini toping.
     
391. 
     Rombning tomoni 20 sm ga, diagonallaridan biri esa 24 sm ga teng. Shu rombning yuzini toping.
     
392. 
     Biror trapetsiyaning o‘tmas burchagi uchidan chiqqan diagonali va yon tomoni, mos ravishda, 26 sm va yf577 sm ga, uning balandligi 24 sm, kichik asosi esa 7 sm ga teng. Trapetsiyaning yuzini toping.
     
393. 
     Teng yonli trapetsiyaning asoslari 7 sm va 13 sm ga, o‘tmas burchagi esa 135° ga teng. Shu trapetsiyaning yuzini toping.
     
394. 
     

5. 
   TEST
   

1. 
   To‘g‘ri burchakli uchburchakning katetlaridan bin 12 sm, gipotenuzasi esa ikkinchi katetdan 6 sm uzun. Gipotenuzaning uzunligini toping.
   

A) 15 sm; B) 25 sm; D) 26 sm; E) 18 sm.

2. 
   To‘g‘ri burchakli uchburchakning gipotenuzasi 25 sm, katetlari o‘zaro 3 : 4 nisbatda. Shu uchburchakning kichik katetini toping.
   

A) 10 sm; B) 15 sm; D) 9 sm; E) 20 sm.

3. 
   To‘g‘ri burchakli uchburchakning katetlaridan bin 12 sm, ikkinchisi esa gipotenuzadan 8 sm qisqa. Shu uchburchakning gipotenuzasini toping.
   

A) 15 sm; B) 16 sm; D) 13 sm; E) 25 sm.

4. 
   Tomonlari 13 sm, 14 sm va 15 sm bo‘lgan uchburchakning eng kichik balandligi necha santimetr?
   

A) 11,5 sm; B) 11,1 sm; D) 11 sm; E) 11,2 sm.

5. 
   Rombning diagonallari 14 sm va 48 sm ga teng. Shu rombning perimetrini toping.
   

A) 60 sm; B) 100 sm; D) 80 sm; E) 120 sm.

6. 
   To‘g‘ri burchakli ABCD (ZD = 90°) trapetsiyaning asoslari 17 sm va 9 sm, kichik yon tomoni esa 15 sm ga teng. AB tomonni toping.
   

A
C7
) 15 sm; B) 17 sm; D) 9 sm; E) 8 sm.