Sinf: 7 Mavzu: Uchburchak ichki burchaklarining yig`indisi haqida teorema. Dars shiori

Berilgan Yechish

A =50⁰ A+ B+ C=180⁰

B=55⁰ 5⁰+55⁰+120⁰=180⁰

C=120⁰ 180⁰= 180⁰


ABC=? Javob: Ha. Sababi berilgan ichki burchaklarimizni yig`indisi 180⁰ ga teng.

2. 
   Berilgan Yechish
   

A =46⁰ A+ B+ C=180⁰

B=150⁰ 150⁰+46⁰+4⁰=180⁰

C=4⁰ 150⁰+50= 180⁰
200⁰≠180⁰
ABC=?


Javob: Yo`q. Sababi berilgan ichki burchaklarimizni yig`indisi 180⁰ dan katta.

3. 
   Berilgan Yechish
   

A=100⁰ A+ B+ C=180⁰

B=20⁰ 100⁰+20⁰+50⁰=180⁰

C=50⁰ 170⁰≠ 180⁰

ABC=?


Javob: Yo`q. Sababi berilgan ichki burchaklarimizni yig`indisi 180⁰ dan kichik.


6-masala: Agar uchburchakning ikkita burchagi: a) 60⁰ va 40⁰; b) 70⁰ va 85⁰; c) 90⁰ va 45⁰; d) 105⁰ va 30⁰ bo`lsa, uning uchunchi burchagini toping.

1. 
   Berilgan Chizma
   

B
A BC
40⁰
A=60⁰
B=40⁰ C x 60⁰ A


C=?


Yechish.

A+ B+ C=180⁰

60⁰+40⁰+X=180⁰
100⁰+X=180⁰
X=180⁰-100 Javob: C=80⁰
X=80⁰

b)Berilgan Chizma

M NK M
70⁰
M=70⁰
N=85⁰
85⁰ x
N K
K=?


Yechish.

M+ N+ K=180⁰

70⁰+85⁰+X=180⁰
155⁰+X=180⁰
X=180⁰-155⁰ Javob: K=25⁰
X=25⁰
c)Berilgan Chizma
Q PR P
45⁰
Q=90⁰
P=45⁰
90⁰ x
Q R
R=?
Yechish.

P+ Q+ R=180⁰

90⁰+45⁰+X=180⁰
135⁰+X=180⁰
X=180⁰-135⁰ Javob: R=45⁰
X=45⁰

d)Berilgan Chizma

B
A BC
30⁰
A=105⁰
B=30⁰ A 105⁰ x C


C=?


Yechish.

A+ B+ C=180⁰

105⁰+30⁰+X=180⁰
135⁰+X=180⁰
X=180⁰-135⁰ Javob: C=45⁰
X=45⁰
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Uyga vazifa: 6-7 masalalar