Question

 Cho tu giac ABCD co goc A= 2 gocB, goc C=3gocD

Tinh so do cac goc 

( neu duoc thi cac ve hinh giup minh voi ) 

Answer 1

Trong tứ giác ABCD, có:

\(\widehat{A}+\widehat{B}+\widehat{C}+\widehat{D}=360^0\left(...\right)\)

\(\Rightarrow2\widehat{B}+\widehat{B}+3\widehat{D}+\widehat{D}=360^0\)

\(\Rightarrow3\widehat{B}+4\widehat{D}=360^0\)

Có: \(360:3=120\), \(360:4=90\)

\(\Rightarrow3.120^0+4.90^0=360^0.2\)

\(\Rightarrow3.60^0+4.45^0=360^0\)

\(\Rightarrow\widehat{A}+2\widehat{B}=180^0;\widehat{C}+3\widehat{D}=180^0\)

\(\Rightarrow\widehat{A}=120^0,\widehat{B}=600^0,\widehat{C}=135^0,\widehat{D}=45^0\)