Question

Tính các góc còn lại của tam giác biết \(\widehat{A}=2\widehat{B}\), \(\widehat{C}-\widehat{B}=36^o\)

Answer 1

Mình thấy đề thiếu 

có phần a,b ko bn !!~~

Answer 2

Xét tam giác ABC có : 

\(\widehat{A}+\widehat{B}+\widehat{C}=180^{\text{o}}\)(1)

=> \(\widehat{3B}+\widehat{C}=180^{\text{o}}\left(\text{vì }\widehat{A}=2\widehat{B}\right)\)

Lại có \(\widehat{C}-\widehat{B}=36^{\text{o}}\)(2) 

Từ (1) và (2) => \(3\widehat{B}+\widehat{C}-\left(\widehat{C}-\widehat{B}\right)=180^{\text{o}}-36^{\text{o}}\)

=> \(4\widehat{B}=144^{\text{o}}\)

=> \(\widehat{B}=36^{\text{o}}\)

=> \(\widehat{A}=72^{\text{o}};\widehat{C}=72^{\text{o}}\)

Answer 3

trả lời :

Xét tam giác ABC có : 

\(\widehat{A}+\widehat{B}+\widehat{C}=180^{\text{o}}\)(1)

=> \(\widehat{3B}+\widehat{C}=180^{\text{o}}\left(\text{vì }\widehat{A}=2\widehat{B}\right)\)

Lại có \(\widehat{C}-\widehat{B}=36^{\text{o}}\)(2) 

Từ (1) và (2) => \(3\widehat{B}+\widehat{C}-\left(\widehat{C}-\widehat{B}\right)=180^{\text{o}}-36^{\text{o}}\)

=> \(4\widehat{B}=144^{\text{o}}\)

=> \(\widehat{B}=36^{\text{o}}\)

=> \(\widehat{A}=72^{\text{o}};\widehat{C}=72^{\text{o}}\)

Answer 4

trả lời :

Xét tam giác ABC có : 

^A+^B+^C=180o(1)

=> ^3B+^C=180o(vì ^A=2^B)

Lại có ^C−^B=36o(2) 

Từ (1) và (2) => 3^B+^C−(^C−^B)=180o−36o

=> 4^B=144o

=> ^B=36o

=> ^A=72o;^C=72o

^HT^

Answer 5

\(\widehat{C}-\widehat{B}=36^o\)

\(\Leftrightarrow\)\(\widehat{C}=\widehat{B}+36^o\)

Ta có :

\(\widehat{A}+\widehat{B}+\widehat{C}=180^o\)

\(\Leftrightarrow\)\(2\widehat{B}+\widehat{B}+\widehat{B}+36^o=180^o\)

\(\Leftrightarrow\)\(4\widehat{B}=144^o\)

\(\Leftrightarrow\)\(\widehat{B}=36^o\)

\(\Rightarrow\)\(\widehat{A}=2\widehat{B}=72^o\)

\(\widehat{C}=36^o+\widehat{B}=72^o\)